What does Acts 7:12 mean?

One effective method to help us better understand the Bible is to interpret it according to the literary genre of the passage. The account of how the Israelites came to Egypt falls under the category of narrative. This part of the story uses the tool of poetic justice.

Nine of Jacob's older sons attacked their younger brother Joseph and sold him to slavers (Genesis 37:12–36). The slavers took Joseph to Egypt and sold him to a nobleman. After serving in a house and then serving time in prison, Joseph rose to the rank of second in command of Egypt. As God's prophet, he knew a famine would come on the land, and Pharaoh empowered him to prepare (Genesis 39—41). As the seven years of famine progressed, Canaan grew desperate while Egypt had food. In another example of God's poetic justice, Joseph's brothers were starving while Joseph had authority over the largest stockpile of grain in the area. When they came to Egypt to buy grain, Joseph hid his identity and thoroughly tested his brothers to make sure they were treating his youngest brother, Benjamin, with more kindness (Genesis 42).

Stephen is using this story to show how throughout Israel's history, they have persecuted those God sent to save them. First, Joseph. Later, Moses (Acts 7:35, 39–40). Most recently, Jesus, the great Prophet Moses said God would raise up—the Messiah (Acts 7:37). God's plans are not thwarted by His people's rejection of His messengers, but Stephen's accusers show the greatest hypocrisy when they claim to follow Moses and his awaited heir but do neither (Acts 6:11–14).