Acts of Apostles in the Early Church 

The writing of history cannot have been Luke's only purpose, for the history he gives us is selective and incomplete.

He tells us about Peter, John, James the Lord's brother and Paul, but nothing about the other apostles, except James the son of Zebedee was beheaded.

He describes the spread of the gospel north and west of Jerusalem, but writes nothing about its progress east and south, except for the conversion of the Ethiopian.

He portrays the Palestinian church in the early post-Pentecost period, but then follows instead the expansion of the Gentile mission under the leadership of Paul.

So, Luke is more than an historian. He is a sensitive Christian "diplomat" in relation to both church and state.

Luke develops a political apologetic, because he is deeply concerned about the attitude of the Roman authorities towards Christianity. He therefore goes out of his way to defend Christians against criticism.

The authorities, he argues, have nothing to fear from Christians. They are neither seditious nor subversive, but on the contrary legally innocent and morally harmless. They in effect exercise a wholesome influence on society.

Perhaps this is why both of Luke's volumes are addressed to Theophilus, which means "loved by God" or "loving God" -- and could symbolize every Christian reader but more likely to be the name of a specific person. 

Luke makes three points as a political apologist...

First, Roman officials were friendly to Christianity, and some had even become Christians, like the centurion at the cross, the centurion Cornelius, and Sergius Paulus, proconsul of Cyprus.

Second, Roman officials could find no fault in either Jesus or his apostles. Jesus had been accused of sedition, but neither Herod nor Pilate could discover any basis for the accusation. 

Third, Roman officials conceded that Christianity was a religio licita (a lawful or licensed religion) because it was not a new religion but rather the purest form of Judaism (which had enjoyed relative religious freedom until the destruction of the Temple).

Luke produced evidence to show that Christianity was harmless, innocent and lawful. Christians should always be able on similar grounds to claim the protection of the state.

Luke was also a peacemaker in the church. He wanted to demonstrate by his narrative the early church was united, that the peril of division was avoided and that the apostles Peter, James and Paul were in fundamental agreement about the gospel.