In what sense is repentance the prior condition of forgiveness?
"Now the hatred of sin, which is the beginning of repentance, first gives us access to the knowledge of Christ, who reveals him-self to none but poor and afflicted sinners, who groan, toil, are heavy-laden, hunger, thirst, and pine away with sorrow and misery (Isa. 61:1-3; Mat. 11:5, 28; Luke 4:18). Accordinlgy, we must strive toward repentance itself, devote ourselves to it throughout life, and pursue it to the very end if we would abide in Christ.... He says, "Do judgment and righteousness, for salvation has come near," (Isa. 56:1).... Yet we must note that this condition is not so laid down as if our repentance were the basis of our deserving pardon, but rather, because the Lord has determined to have pity on men to the end that they may repent, he indicates in what direction men should proceed if they wish to obtain grace.... Therefore, I think he has profited greatly who has learned to be very much displeased with himself, not so as to stick fast in this mire and progress no farther, but rather to hasten to God and yearn for him in order that, having been engrafted into the life and death of Christ, he may give attention to continual repentance."
~Institutes Book III: 20.
Question: How are we to understand what appears to be the conditionality of abiding in Christ, which is based on a continual life of repentance (1st set of italics), and the simultaneous teaching of believers living a life of repentance as a result of "having been engrafted into the life and death of Christ" (2nd set of italics)?
Christians are often perplexed at statements such as these, which imply a call to obedience with the warning of punishment for a lack of obedience. This is definitely because Christians have a low view of God's holiness, a low view of sin, and a sorry state of easy-believism steering them through life.
Calvin affirms that Christians have union with Christ, and this is the starting point. God has called us to be holy, and since we have union with Christ we are therefore called to live a life of dying to sin, a life of yearning for holiness and a life of repentence. For the way in which we go after these things is by living a life of repentance. We turn from sin, and we do righteousness. We confess our sins, not to avoid the wrath of God, but because our loving heavenly Father is displeased with the sin. We are forgiven of all our sins, we have union with Christ, and the way in which we grow in Christ toward holiness is by living lives of humble submission to his loving care.