Your question about repentance is timely, as Brad, myself and several other brothers here in Logan have been discussing it at length. We recently discovered an outstanding little book on the subject written in the late 19th century, which you must get your hands on. It's called "The Great Meaning of Metanoia" by an Episcopalian minister named Treadwell Walden. He wrote it about a month after the Revised Version of the Bible was published, which was anticipated to be a corrective translation of the traditional English version (KJV). Unfortunately, the Revised Version left untouched the word "repentance", and Walden wrote to express his disappointment. Scholars who worked on the Revised Version and other New Testament professors wrote to Walden expressing their support of his position, admitting that the word "repentance" is a bad translation of "metanoia", for it doesn't carry the word's meaning at all. Walden's original essay is brilliant and full of apostolic character which is often so lacking in traditional Christianity. The book is out of print, but the University of California Library prints it on demand for somewhere between $15-$20 dollars (here). I think it is worth every penny.
Simply put, metanoia is a word filled with remarkable meaning by the preaching of Christ and the apostles. It is not a word that comes replete with it's own meaning. The English word "repentance", on the other hand, comes filled with it's own meaning - it needs no supplementation by context. Repentance means to feel remorse or regret for your sins; it's Latin root literally means "pain; suffering in view of being liable to punishment". Metanoia has no such meaning associated with it. The word is Greek, and it is made up of two words: meta & nous. Meta means "after" or "change", and nous is the Greek word for "mind". The word means "after-mind" and signifies a change of mind: thinking one way, but then afterwards thinking another. It is the opposite of pronoia (pro-nous) which means before-mind: the mind or thinking you have before. Interestingly, there is another Greek word we frequently use in English that is related to metanoia: it is paranoia (para-nous). Literally, the word means to be beside-mind, or we would say "out of your mind", or "beside yourself". Paranoia is not being in a right mind, but having a mind that is off center - that is, not where it should be (http://www.etymonline.com/index.php?term=paranoia&allowed_in_frame=0). If you compare metanoia and paranoia together, you get the idea of what the New Testament call for metanoia is: it is a command to change your mind and get it where it should be.
Of course, metanoia, when used as a command ("change your mind") needs supplementation by context; it needs to be filled with more information because we need to know what we are supposed to change our mind about. It can be something small (metanoia about how to spell "judgment"), to something enormously large (metanoia about your religious worldview). The sky is the limit with metanoia, and that is precisely the point of the remarkable function of the word in the New Testament. It is not restricted, like "repentance", to a narrow meaning of pain and sorrow for sin, which we then have to force unnaturally to fit with the gospel. It is a change of mind unto the gospel itself. The gospel is what the change of mind is about. The preaching of Jesus and the apostles speaks to the nous and men change or don't change their mind as they hear it. When a man changes his mind at the preaching of the gospel, he has experienced metanoia. Thus, the proclamation of metanoia at the beginning of the New Testament is the doorway into the entire rest of the doctrine of the New Testament: Change your mind! About what? Listen! A radical mindshift in the religious world is about to happen... no, it is happening now... What we thought about God and the law and righteousness and forgiveness is all about to change. Hear! Metanoia and believe the gospel!
New Testament metanoia is a divine call to a radical mind-shift in the way men think about religion. Therefore "repentance" is an entirely unsatisfactory translation of the amazing word "metanoia" which gives a completely different feeling to the preaching of Jesus and His apostles. Was the major proclamation of Jesus and the apostles "Repent! Feel sorry for your sins"? Or was it "Metanoia! Think a new way"! Do you see what a difference these two words make? Which one is in keeping with the gospel of grace as we know it from the New Testament? Not the first, but the second. The gospel calls us to a new way of thinking about religion. Whereas men think that they are good, and that obedience to the law is the way of salvation, and that the law only requires partial obedience, and that most people won't perish, Jesus calls us to believe that there is none good, and that no one will be saved by obedience to the law, because the law requires perfect obedience, and that broad is the road that leads to destruction. The apostles call us to believe that the cross of Christ is the power and the wisdom of God, the only way whereby we are saved, and live, through faith, while the world thinks that the cross is foolishness. Which word best summarizes this kind of preaching: "repent", or "metanoia"? Certainly not the first, but the second.
How did we lose this apostolic feature from our understanding and preaching of the gospel? Our loss of the meaning of metanoia came from early Latin Christianity, which failed to comprehend what was happening in the New Testament. It failed to understand the meaning of the gospel of grace, and envisioned Christianity to be primarily concerned with amending men's behavior - in which Jesus, the God-man, came to teach men the highest principles of piety and morality. In keeping with this sentiment, the Latin Vulgate made the colossal error of translating "metanoia" as "poenitentiam agite" (do penance). But how could they do this, since the two concepts are so radically different? It is because the early Latin scholars, who indeed recognized that the Greek word "metanoia" meant to "change the mind", did not understand what the New Testament gospel of grace was all about, and consequently, since the word is hollow and requires filling, they filled the word metanoia with something other than what Christ and the apostles filled it with. They interpreted the mind-change as changing your mind about how you are behaving - to regret your sinful lifestyle and to amend your life, rather than as changing your mind about the way of righteousness - that righteousness does not come through the law but through faith in Christ. Having interpreted the call to change your mind this way, the Latin scholars thought it would be more helpful to skip the more hollow word "metanoia" with the fuller paraphrase "poenitentiam agite", which they believed best communicated the purpose of the mind change. Thus they paraphrased the word metanoia as they thought best; they did not translate the word. And it stuck. The Latin Vulgate possessed sole and unquestioned authority for over one thousand years, and therefore this erroneous paraphrase, "peoenitentiam agite" (do penance), became deeply rooted in the Church's vocabulary and teaching.
By the time of the Reformation, the doctrine and practice of penitence ("repentance") was so assuredly believed to be Biblical that even the Reformers could not see clearly enough to root it out of their own systems. Though they rightly saw afresh that the gospel of Jesus Christ was all about righteousness through faith apart from works, they continued to confuse "metanoia" with penitence, and the rest of Protestant history has been an awkward and uncomfortable effort to somehow fit the necessity of repentance alongside the proclamation of sola fide. The proposed solution to the problem was to move repentance from one side of salvation to the other; so that, instead of having to repent in order to be saved (as the Roman Catholics saw it), the Reformers argued that repentance was a fruit and effect of being saved. In this way, salvation produced the amended life, but was not dependent upon it, so preserving the gospel of grace. However, while it indeed is true that salvation produces the transformed life and not the other way around, the Scriptures remained clear that Jesus and the apostles preached that in order for men to be saved, they must "metanoia" (ex. Luke 13:3, Acts 3:19, etc.) - and the real problem was not in the order of salvation and repentance, but in the word "repentance" itself. The Roman Catholics understood the order correctly, but had the wrong definition of metanoia, while the Reformers understood the order incorrectly, and likewise had the wrong definition of metanoia! This incorrect order and definition has caused the strange unapostolic juggling of sola fide and repentance within Protestantism, a juggling we have has seen for the last 500 years, and which is still just as prevelant today. All that is needed for the juggling to stop is to simply see the true meaning of metanoia.
I believe that one of the greatest perpetuating sources of this error within Protestantism is the Westminster Confession of Faith - the impressive and definitive English statement of Reformed theology - which is defended and taught zealously in the majority of Reformed churches. I truly appreciate much in the Westminster Confession, but I believe it is in grave error when it defines "repentance" as follows (underlines mine):
I. Repentance unto life is an evangelical grace, the doctrine whereof is to be preached by every minister of the gospel, as well as that of faith in Christ.
II. By it a sinner, out of the sight and sense, not only of the danger, but also of the filthiness and odiousness of his sins, as contrary to the holy nature and righteous law of God, and upon the apprehension of his mercy in Christ to such as are penitent, so grieves for, and hates his sins, as to turn from them all unto God, purposing and endeavoring to walk with him in all the ways of his commandments.
III. Although repentance be not to be rested in as any satisfaction for sin, or any cause of the pardon thereof, which is the act of God's free grace in Christ; yet is it of such necessity to all sinners, that none may expect pardon without it.
IV. As there is no sin so small but it deserves damnation; so there is no sin so great that it can bring damnation upon those who truly repent.
V. Men ought not to content themselves with a general repentance, but it is every man's duty to endeavor to repent of his particular sins, particularly.
VI. As every man is bound to make private confession of his sins to God, praying for the pardon thereof, upon which, and the forsaking of them, he shall find mercy: so he that scandalizeth his brother, or the Church of Christ, ought to be willing, by a private or public confession and sorrow for his sin, to declare his repentance to those that are offended; who are thereupon to be reconciled to him, and in love to receive him. (WCF, XV, Repentance Unto Life)
Notice the juggling that takes place in this explanation of "repentance". Repentance is not to be rested in as the cause of our salvation, but yet you dare not rest unless you have repentance! Repentance is necessary for the sinner, as well as faith in Christ! This is simply unbiblical and unevangelical. It does not carry with it the free and gracious character of the New Testament gospel, but rather attaches to the free offer of the gospel an awkward and burdensome system of penance - that residual vestige of old Latin theology. The Reformers, while seeing correctly that righteousness comes by faith alone in Christ alone, failed to see the beautiful meaning of metanoia. Metanoia is but the change of mind to this gospel, and it is the call for men who are ignorant of the righteousness of God by faith to see this new and living way of righteousness in Christ and the futility of their own attempt to be righteous by the law. But the Reformers, unable to see past the deeply entrenched Latin concept of poenitentiam agite to the original apostolic meaning and preaching of metanoia, were left with nothing else to do but juggle awkwardly in order to be faithful to Scripture and to preserve the gospel they had come to see and love.
It would be helpful to ask any Reformed Christian if they have "repented" according to the definition of the Westminster Confession of Faith. Have they "turned from all their sins unto God, endeavoring to walk with Him in all the ways of His commandments?" Have they "repented of their particular sins, particularly?" And if not, does this mean that they are not saved? Of course, they will admit that no one has, but experience has typically shown that rather than admit the Confession is wrong, the standards get lowered so that people can feel like they have repented. If we don't lower the standards and are honest about our sins, we will admit that none of us truly feel sorry for all our sins, and none of us have turned from all our sins particularly, nor do we obey all the commandments. If we did, we wouldn't be sinners! But the gospel is the good news for sinners, that as sinners, we are "justified freely by His grace, through the redemption that is in Christ Jesus" (Rom. 3:24) through nothing but faith alone. "To the one who does not work, but believes upon Him who justifies the ungodly, his faith is counted unto righteousness." (Rom. 4:5) Reformed churches believe this! Why not then drop the the erroneous and awkward doctrine of "Repentance unto Life" for the Scriptural and apostolic doctrine of metanoia unto life?
"Whosoever will, let him take freely of the waters of life." (Rev. 22:17) "'Sirs, what must I do to be saved?' And they said to him, 'Believe on the Lord Jesus Christ, and you shall be saved." (Acts 16:30-31) "The Lord is... not willing that any should perish, but that all should come to metanoia." (2 Pet. 3:9) God calls sinners to eat freely of the bread of life, the broken body and shed blood of His Son. This is a meal He has set for the ungodly, not for the righteous nor for some phony level of righteousness. He wants sinners to eat of it, and He does not set up signs that say: "Only for those who are penitent". God sees our dire need and says, "Eat, sinner, and live! Believe on the Lord Jesus Christ! Look and your soul shall be filled! Do not think that you must worthy to receive My salvation. Behold and believe My righteous generous grace for you displayed in the cross of Christ. Metanoia!"
I hope this is helpful to you, J---. I love you, dear brother, and pray for you to have wisdom and clarity in this matter. Looking forward to hearing from you again,