1 Corinthians 10:16-17, Communion of the Body of Christ
Believers are a joined as one body in Christ through faith in the one act on the cross where Jesus’ broken bodily offered as sacrifice for our sake to save us from our sins.
Through that one offer of Christ on the cross, we by faith receive forgiveness of sins. The Lord’s Supper was instituted by our Lord Jesus before He went to the cross to help His people remember His death till He comes again. That they may not forget that there was no greater love than this, no greater sacrifice than this, no greater suffering than this.