Sin After Justification

Not every sin willingly committed after justification is the sin against the Holy Spirit, and unpardonable. After we have received the Holy Spirit, we may depart from grace given and fall into sin — and by the grace of God, rise again and amend our lives. Those who say they can no more sin as long as they live here, or deny the place of forgiveness to such as truly repent, are to be condemned.

If we confess our sins, he is faithful and righteous to forgive us the sins, and to cleanse us from all unrighteousness.
— 1 John 1:9 (WEB)

Note

Methodist theology rejects "once saved always saved" in its absolute form. A believer can fall — and can also rise again by grace.

Bible references

1 John 1:8-10 · 1 John 2:1-2 · Hebrews 6:4-6 · Hebrews 10:26-31 · 2 Peter 2:20-22 · Galatians 6:1