Only God giving us rebirth actually changes us.You said repentance doesn’t make us Christians, but the Bible says in Acts 3:19, “Repent ye therefore, and be converted, that your sins may be blotted out.” That shows repentance and conversion go hand in hand. No one gets saved without turning to God. In Acts 2:38, Peter told the crowd, “Repent, and be baptized... for the remission of sins.” Repentance comes first, not after.
And no, I'm not saying we don't repent until God rebirths us.
Romans 6:4-10 KJV
4) Therefore we are buried with him by baptism into death: that like as Christ was raised up from the dead by the glory of the Father, even so we also should walk in newness of life.
5) For if we have been planted together in the likeness of his death, we shall be also in the likeness of his resurrection:
6) Knowing this, that our old man is crucified with him, that the body of sin might be destroyed, that henceforth we should not serve sin.
7) For he that is dead is freed from sin.
8) Now if we be dead with Christ, we believe that we shall also live with him:
9) Knowing that Christ being raised from the dead dieth no more; death hath no more dominion over him.
10) For in that he died, he died unto sin once: but in that he liveth, he liveth unto God.
Much love!