While most here would know full well that these three things are not the same, I would like us to explore the the differences and the interrelationships between the concepts.
Scenario 1: I commit a sin against you. I know that what I have done is wrong. If I were a hardened criminal, or a gangster, I probably would think no more of the matter. But, being Christian, I regret what I have done. When this regret leads me to being more careful so that I do not do this sort of act again, that is repentance, a turning away from wrongdoing. So my first point is that repentance leads to a change in actions so as to avoid committing the same sin again.
You have a choice about how you deal with me. If I try to apologise, you can either accept or reject the apology, and there is nothing I can do about your response. I can only control my own actions and intentions. If you decide that you will accept my apology and while ensuring that you do not end up in such a position that I can sin against you again, I would call that a learning experience. You may or may not bear me a grudge for what I had done. If you do not bear a grudge, and thoughts of what went wrong are not filling your every waking moment (OK, poetic licence) then you will almost certainly have forgiven me. Even when I do not try to apologise, or think nothing of what I have done to you to cause you pain, you still have the choice of forgiving or not. This is your choice. My behaviour after the event can make this easier for you or harder for you, but it does not remove the choice.
You can forgive me for this but our relationship is still strained because you do not fully trust me not to do the same thing again. This is more likely when I do not repent of my sin. Again I would suggest that this is simply self protection on your part.
But reconciliation is only truly possible when there has been a sufficient build-up of trust to enable us to be able to allow ourselves to be vulnerable to the other to something like the level that existed previously.
Scenario 2 A preacher preaches a heresy from the pulpit. He or she claims that the traditional Christian understanding is “too fundamentalist” for a post modern world. He or she does not have the sermon written down so there is no way that anyone who was not present can tell exactly what was or was not said. Many of us would say that the preacher should be challenged is they have clearly strayed from orthodox Christian belief, but in the congregation where I worship, there are many who simply assume that anything from the pulpit has got to be the Gospel. On being challenged, the preacher is unrepentant, in fact accusing those in the congregation who have challenged the theology preached of being narrow-minded dogmatists who are unwilling to explore the way their faith should be worked out in the world.
Aside from the fact that the leaders of a church will be held to a higher standard than the followers, should the challengers forgive the preacher. I think that we have the instruction from Scripture, as given to Peter, to seventy times seven. Having been forgiven, should the preacher be invited to preach again? If the answer is no, does that mean the congregation has not forgiven the preacher?
The leaders of any local church have a responsibility to God for the care of the congregation. That care includes, but is not limited to ensuring that when the Word is preached, the congregation hears the true Gospel and not some heretical rehash that tells us black is white. If the preacher did that on a road safety lesson, we would all be in danger of being run over on a zebra crossing(H/T Douglas Adams). Unfortunately, too often poor teaching means that the congregation are not told that they have a responsibility to weigh up the preaching to see whether it is orthodox or heretical, to take heed of the orthodox and to reject the heretical.
Can Truth be reconciled to heresy? Does not light overcome darkness. Sometimes, even with forgiveness, there still cannot be reconciliation because there is a need to protect others from sin. In Scenario 2, until and unless the preacher comes to an understanding that God’s truth is outside of time and of culture, and is universally valid for all peoples in all ages and at all times, and should not be ‘reinterpreted’ to mean something that it clearly does not mean. Someone more wise than i said, “If you find that your interpretation of a passage of Scripture is different from what it was 1900 years ago, and 1500 years ago, and 1000 years ago, and 500 years ago and 100 years ago and even 50 years ago, consider for a moment the modest thought that you might be wrong”
The powers that were in Palestine 2000 years ago were not terribly impressed with Jesus message then, because it meant that they had to consider that they had to consider that they might be wrong, and had Him killed. Roman emperors felt similarly and had many Christian killed both as scapegoats for things had had not gone according to their plans and for entertainment. We can expect that preaching Jesus in the here and now will have similar results, especially if we have sufficient evidence to enable us to be convicted in a court of law for being Christian. There was no reconciliation then, except for the fact that it was made possible through the death of our Lord for those who believe in His name. We need to know what we believe because faith in the wrong god is futile. There is no point in making a god of money, or atatus or power, or anything else that w=the world chases after. We need to know the Source and perfecter of our faith.
So how do we communicate this need to know Who to believe to the ordinary members of the congregation?