The Lord's Supper is an institution ordained by Jesus so that we might remember His death until He returns. (Matthew 26:26-29; 1 Corinthians 11:23,26)
Jesus instituted the Lord's Supper that His followers might "shew the Lord's death till he come" (1 Corinthians 11:26). This observance points back to Christ's death on the cross, and forward to His coming to earth again.
The Bible instructs us that we are to examine ourselves before we partake of the emblems which represent His broken Body and Blood. The one who takes part in this ordinance must allow God to search his heart, and thus measure his life by the Word, lest he "eat this bread, and drink this cup of the Lord, unworthily."
Matthew 26:26-29; Luke 22:17-20; 1 Corinthians 11:23-26