The Bible places two activities in man’s hands and before salvation which is man’s part in responding to the offer of God: repentance and faith. In actuality, both of these things are really different views of a single one thing, responding in submission to the will of God.
Submission to the will of God is what saves us, not because it is a good work with we do that produces merit before God on our account, but because man is in rebellion against God, and this action of doing the will of God in good will, desire, and with a good attitude, this is what God responds to in our life. It is to unite with God in His will.
Repentance means a change of mind. Repentance has two basic elements and an action towards both. The two elements are (1) the will of God, and (2) some other will which is not God’s will. Repentance is the action of releasing and abandoning that other will in order to wholehearted do the will of God.
It is a single action of turning from, and turning to.
Repentance is not a one time thing, like going forward after a moving sermon to kneel at an altar. Repentance is a mental and spiritual activity in which we change our life from our will to God’s will. For those who would say that it is impossible to do that, why? Does not God want everybody to do His will? Yes. Would not God be active and powerful in supplying us with the divine spiritual part in this activity to obey God? Yes.
Repentance “begins” at some part in our wicked lives, and after that, we come to know Christ. But every true believer will live repentance throughout his life, practicing repentance at every turn of his life in following God.