There is no ‘getting better’ from SIN; there’s no amount of discipline or ‘growth’ that can drive it from you.

The ONLY way to be rid of its stench and blackness is to surrender all of it to Christ and absolutely trust Him. You see, He took the penalty for ALL of it that we surrender by faith on the cross of Calvary. He literally took all of it on Himself:

who Himself bore our sins in His own body on the tree, that we, having died to sins, might live for righteousness—by whose stripes you were healed. (1Pet 2:24 )