Let’s look at the first reading. It gives us the opening lines of the letter Paul wrote to the Christians in Rome before he had met any of them. Seeing himself as something very lowly, yet very exalted, he calls himself a slave, then he turns that around, declaring himself to be on a level with the twelve Apostles chosen by Jesus.
Although St. John will later insist that Jesus was one with God from the first moment of his being, Paul had not as yet grasped that fact. So, he says, in the flesh Jesus was descended from David, but he was only declared Son of God at his resurrection.
St. Luke seemed to have had the same uncertainty about Jesus. In Chapter Two of the Acts of the Apostles he tells us that after his death Jesus was lifted to the right hand of God; and it was then that he received the “Promised Holy Spirit.”
When we have trouble getting a clear grasp on what Our Lord was made of, we needn’t be ashamed. It took Paul and Luke time to take it all in.