Stephen answered the high priest saying the God of glory appeared to Abraham when lived in Mesopotamia and said to leave his country and relatives and come to the land He would show him. After Abraham's father died in Haran, God brought him to Israel and gave it to him and his offspring as a possession. They would be slaves and mistreated in a foreign land for 400 years. God would judge Egypt and allow them to come out and serve Him. Abraham became the father of Isaac with Jacob his grandson who had 12 sons as patriarchs. Jealousy led the patriarchs to sell Joseph into Egypt. God rescued him from all afflictions and made him governor over Egypt and his household. When famine came in Egypt and Canaan, Joseph made himself to known to his brothers. Joseph invited Jacob his father and 75 relatives when they heard about the grain there. The people multiplied fulfilling God's promise to Abraham before Moses was born (Acts 7:1-19). Abraham received God's promise of possessing land and descendants unconditionally.
The Egyptians educated Moses and he became powerful in words and deeds. After taking vengeance when an Israelite was mistreated, Moses fled to Midian. After 40 years, an angel appeared in a burning bush to tell Moses to rule and deliver the Israelites. He performed wonders and signs in Egypt, Red Sea and wilderness for 40 years. Moses received living oracles on Mt. Sinai that they disobeyed by making a golden calf and worshiping Mooch and Rompha. Moses instructed them on how to build the tabernacle of testimony that Joshua brought while dispossessing the nations until the time of David (Acts 7:20-45). Moses received God's promise concerning unconditional ownership of the land, but enjoyed his relationship with God through obedience.
David asked to find a dwelling place for the God of Jacob, but Solomon built a house for Him even though the Most High does not dwell in houses made by humans since heaven is His throne and the earth His footstool. You men always resist the Holy Spirit and disobey the law like your fathers that killed the prophets who announced the coming of the Righteous One (Acts 7:46-53). David received God's promise of establishing His house, kingdom and throne eternally and unconditionally once he gave up control.
They were convicted by Stephen's preaching and began gnashing their teeth at him. Stephen was full of the Holy Spirit, saw the glory of God and Jesus standing at the right hand of God. They began stoning him and the witnesses laid their robes at the feet of Saul. Stephen called upon the Lord and cried out, "Lord, do not hold this sin against them!" and then died (Acts 7:54-60). Preaching and teaching God's covenants with Abraham, Moses and David convict people of sin and lead to dramatic response.
Do you understand God's covenant to Abraham, Moses and David? If not, study Gen. 12-15; Deut. 28-30; and 2 Sam. 7. What difference does it make in helping you understand the gospel of Christ?