What does the Bible say about departing from a church?

Scripture encourages believers to view a brother or sister's departure from a church with a spirit of prayer and hope rather than condemnation. In 1 John 5, John expresses that when believers see a brother sinning, they should pray for him, trusting that God may chasten or redirect him into a new church where the gospel is preached in truth. The key distinction lies in understanding that a true believer will not completely forsake Christ or the assembly of the saints but may simply be in need of correction or discipline, which God often provides. Therefore, the principle is that a child of God, while capable of failing, will ultimately return to a true assembly where the gospel is faithfully preached.