How does the Church exercise its authority to judge? (Q80)
From To Be A Christian, An Anglican Catechism
A priest, acting under the authority of the bishop, may bar a person from receiving communion because of unrepented sin, or because of enmity with another member of the congregation, until there is clear proof of repentance and amendment of life. But the authority Christ gave to his Church is more often exercised by declaring God's forgiveness in absolution. (Matthew 16:19)