[for me anyway] it is as simple as the Lord Jesus Christ defines it saying "Go and sin no more": for if I am a thief, I must stop stealing in order for it to be worthy of repentance; or if I am a liar, then I must stop lying in order for it to be worthy of repentance: and so it is with every (known) sin that we have.
Repenting is to "feel pain" the pain of guilt for our sin that touches the heart, and causes us to amend our ways and doings: or again simply put, if I am a thief, them I have to stop stealing, and nothing wavering.
By the way guilt is a gift of God for our sake, for if we were to sever ourselves from the pain of guilt, then we would be as the unbelievers who dismiss sin as sin, and instead proceed from sin to sin.
Repenting is to "feel pain" the pain of guilt for our sin that touches the heart, and causes us to amend our ways and doings: or again simply put, if I am a thief, them I have to stop stealing, and nothing wavering.
By the way guilt is a gift of God for our sake, for if we were to sever ourselves from the pain of guilt, then we would be as the unbelievers who dismiss sin as sin, and instead proceed from sin to sin.