“Repent ye therefore, and be converted, that your sins may be blotted out, when the times of refreshing shall come from the presence of the Lord.”- Act 3:19

Repent signifies, in its literal meaning, to change one’s mind. It has been translated, “after-wit,” or “after-wisdom;” it is the man’s finding out that he was wrong and rectifying his judgment…Repentance is a discovery of the evil of sin, a mourning that we have committed it, a resolution to forsake it. It is, in fact, a change of mind of a very deep and practical character, which makes the man love what once he hated, and hate what once he loved. Conversion, if translated, means a turning round, a turning from, and a turning to-a turning from sin, a turning to holiness-a turning from carelessness to thought, from the world to heaven, from self to Jesus-a complete turning. The word here used, though translated in the English, “Repent and be converted,” is not so in the Greek; it is really, “Repent and convert,” or, rather, “Repent and turn.” It is an active verb, just as the other was. “Repent and turn.” When the demoniac had the devils cast out of him-I may compare that to repentance; but when he put on his garments, and was no longer naked and filthy, but was said to be clothed and in his right mind, I may compare that to conversion. When the prodigal was feeding his swine, and on a sudden began to consider and to come to himself, that was repentance. When he set out and left the far country, and went to his father’s house, that was conversion. Repentance is a part of conversion. It is, perhaps, I may say, the gate or door of it. It is that Jordan through which we pass when we turn from the desert of sin to seek the Canaan of conversion. Regeneration is the implanting of a new nature, and one of the earliest signs of that is a faith in Christ, and a repentance of sin, and a consequent conversion from that which is evil to that which is good. ~ C.H. Spurgeon

https://www.blueletterbible.org/Comm/spurgeon_charles/sermons/0804.cfm