...because the letter kills but the Spirit gives life. (2 Corinthians 3:6)
See Ephesians 4:25- 5:21 and Colossians 3:5-24 for what to put off and put on.
Galatians 5:19-26 for the deeds of the flesh vs. the fruit of the Spirit
adultery, fornication, uncleanness, lewdness, idolatry, sorcery, hatred, contentions, jealousies, wrath, selfish ambition, dissension, heresy, envy, murder, drunkenness, revelry, passion, covetousness, malice,blasphemy, filthy language, lying, stealing, corrupt speech, bitterness, clamor, foolish talking, coarse jesting, pride, boaster, strife, whisperers, backbiting, untrustworthy, unloving, unmerciful, disobedience to parents, violence
love, joy, peace, longsuffering, kindness, goodness, faithfulness, gentleness, self-control, tender mercies, humility, meekness, forbearance, forgiveness, thankfulness, truthfulness, work, edifying speech, grace, righteousness, redeeming time, spirit-filled, speaking/singing/teaching one another with various songs, submitting appropriately, obey and honor parents, prefer and honor others, selflessness, compassion
...by spending time memorizing and meditating on the Scriptures. (Psalm 1:1-3; Joshua 1:8)
Train yourself in godliness. (1 Timothy 4:7)
Because breaking bad sinful habits requires the practice of new habits.