...to the place of the altar which he had made there at first. And there Abram called on the name of the Lord... Then Abram moved his tent, and went and dwelt by the terebinth trees of Mamre, which are in Hebron, and built an altar there to the Lord. - Genesis 13:4, 18
Altars are a memorial to the place where God meets us
Altars represent the occasion and place where we have had a personal encounter with God. We may not always be able to make a physical altar, but there can be one established in our hearts. When we celebrate communion, we are celebrating the grandest altar of all--the Cross of Calvary upon which the Son of God was laid forth as the sacrifice: To reconcile all humankind to God; and to make possible the infusion of our lives with meaning, the forgiveness of all sins and the promise of eternal life.
Altars appear throughout the Bible in many different forms. They are: