This question is for Unitarians/Biblical Unitarians as well and it is based on Acts 7:59-60

Acts 7:59-60 >**59** And they went on stoning Stephen as he called upon the Lord and said, "Lord Jesus, receive my spirit! **60** And falling on his knees, he cried out with a loud voice, "Lord, do not hold this sin against them!" And having said this, he fell asleep. Why did not Stephen call upon the "only true God?" It's interesting that Stephen's confession and Jesus' confession (Luke 23:34), there is a striking contrast; Jesus "commended" His spirit to the Father but Stephen, to the Lord Jesus Christ, why?