Abraham, Isaac, and Jacob were not just men who believed in God from a distance. They lived before God. They moved when God told them to move. They built altars where God appeared to them, and they called upon the name of the Lord. Their worship was not separated from their family life, their land, their covenants, or their daily walk. The altar was the place where they acknowledged God, remembered His promises, and gave themselves again to the way He had shown them.
Abraham's altar worship began when the Lord appeared to him in the land of Canaan and promised that his seed would inherit the land. Abraham did not just hear the promise and move on. He built an altar there unto the Lord who appeared unto him (Genesis 12:7). Then he moved to the mountain east of Bethel and built another altar, and there he called upon the name of the Lord (Genesis 12:8). This shows a lovely pattern in Abraham's life. When God appeared, Abraham worshiped. When Abraham moved, he carried that worship with him.
After that Abraham returned to the place of the altar which he had made at the first, and there he called on the name of the Lord again (Genesis 13:3-4). Then God told him to lift up his eyes and look over the land, and promised it to him and to his seed forever. God also told him to arise and walk through the land, for He would give it unto him (Genesis 13:14-18). So Abraham's altar was not just a place of prayer. It was tied to instruction, covenant, inheritance, and obedience.
Abraham also received instruction from God in sacrifice when the Lord told him to bring the heifer, the goat, the ram, the turtledove, and the young pigeon (Genesis 15:7-18). The word altar is not used there, but the meaning is still very strong. God was teaching Abraham through sacrifice and covenant. Then years later came the great test with Isaac. God told Abraham to take Isaac and offer him for a burnt offering, and Abraham built the altar and laid the wood in order (Genesis 22:2, 9-18). God stopped him before Isaac was harmed, and then confirmed the covenant with an oath. What a hard and holy moment that must have been. Abraham saw God as the One who commands, proves, provides, and keeps covenant.
Isaac's altar worship was quieter in the record, but it followed the same family pattern. God appeared to Isaac and told him not to go down into Egypt, but to dwell in the land He would show him. Then God renewed the promise given to Abraham, promising to bless him and multiply his seed (Genesis 26:2-5). Isaac was being taught that the covenant was not only something his father had received. It now rested upon him also.
Later Isaac went to Beer-sheba, and the Lord appeared unto him that same night. God told him not to fear, for He was with him, and would bless him and multiply his seed for Abraham's sake. Then Isaac built an altar there, called upon the name of the Lord, pitched his tent there, and his servants digged a well (Genesis 26:23-25). That is a wonderful picture. Worship, family dwelling, and the work of providing water were all together. Isaac saw God as the God of his father Abraham, but also as the God who was now with him.
Jacob's life also turned around sacred places where God appeared. At Bethel, while Jacob was fleeing from Esau, he dreamed of a ladder set up on the earth with the top reaching to heaven, and the Lord stood above it and gave him the promise of land, seed, and blessing (Genesis 28:10-22). Jacob set up the stone for a pillar and poured oil upon it. It was not yet called an altar, but Jacob knew God had met him there.
Years later God reminded Jacob of that place, saying, "I am the God of Beth-el," where Jacob had anointed the pillar and vowed a vow. Then God commanded him to leave the land where he had been dwelling and return to the land of his kindred (Genesis 31:13). Jacob later built an altar at Shalem and called it El-elohe-Israel, meaning God, the God of Israel (Genesis 33:18-20). This shows that Jacob was beginning to understand God not only as the God of Abraham and Isaac, but as his own God.
Then God gave Jacob a direct command. He told him to arise, go up to Bethel, dwell there, and make an altar unto God, who had appeared to him when he fled from Esau (Genesis 35:1). Jacob obeyed and told his household that he would make an altar unto God, who answered him in the day of his distress and was with him in the way he went. Then he built the altar at Bethel and called the place El-beth-el, because God appeared unto him there (Genesis 35:3, 7). After that God appeared to Jacob again, blessed him, gave him the name Israel, and renewed the covenant promise of land and seed (Genesis 35:9-15).
Near the end of Jacob's life, he came to Beer-sheba and offered sacrifices unto the God of his father Isaac. Then God spoke to him in visions of the night and told him not to fear going down into Egypt, for God would go with him and bring him up again (Genesis 46:1-4). Jacob saw God as the God who had followed him through fear, exile, family trouble, covenant promise, and old age. God had been with him in the way.
So Abraham, Isaac, and Jacob each knew God at the altar. Abraham saw God appear, command, covenant, and provide. Isaac saw God continue the promise and give him peace in the land. Jacob saw God in dreams, visions, commands, and covenant renewal. Their altars were not dead religious places. They were living places of meeting. God spoke, and they answered with worship. God promised, and they built. God led, and they moved.