Exposition:
God from time to time revealed Himself to Abram and reaffirmed his promises to him. In Genesis 13, God revealed himself to Abram after Lot left and affirmed His promises to him. God confirmed His promise once again to Abraham by giving him success in his pursuit to bring back Lot, his family and all his property after the impasse. Similarly, God’s response in Genesis 15 sets up a ceremony to reaffirm His covenant with Abram following a complaint Abram laid before Him. Abram’s complaint shows that he took God seriously and he responded to the revelations of God by building altars of prayer and worship. We see in the life of Abram the building of altars right from his departure to the land God intended for him. He built them to acknowledge the presence of God, worship God, pray to God and, also, as a reminder of the things God promised him.
When God calls you, He continually shows Himself in so many ways to affirm and assure you of His promises until His divine time for its fulfilment is up. God expects you to respond with faith as Abram did by worshipping and acknowledging Him. Building the altars helped Abram remember that God was at the centre of his life. Regular worship helps us remember what God desires and motivates us to obey Him aside bringing us closer to God. How many altars of worship have you built as a child of God and as a servant of God since He called you? What reminds you of God’s promises? At times it’s alright to ask God questions but do it out of faith in Him like Abram did, not in doubt of His promises.