Like Faith, True Repentance is from a Spiritual Source, its the Gift of God, not of works lest any man should boast. Repentance thats towards God can be that which leadeth to Godly sorrow 2 Cor 7:10
For godly sorrow worketh repentance to salvation not to be repented of: but the sorrow of the world worketh death.
So this being true, this type of repentance in regards to salvation is from a godly source ! That godly source cant be out from the flesh of sinful man, which I believe can only worketh or lead to death !