On the cross, was Jesus speaking to God the Father or to Himself?
On the cross, Jesus was not merely speaking to Himself as a man; He was God the Son addressing God the Father. The context describes it as God speaking to God, since the triune Godhead is complete and in absolute consensus. Christ's words from the cross were communication within the Godhead, the Word speaking to the Father.
Les explains that Martin Luther had a real hang-up with Christ's statements from the cross when Jesus seemingly spoke to God. Luther concluded, "Well, it's God speaking to God," and Les agrees: absolutely, it was. Because the triune Godhead was complete and in absolute consensus, the Word—God the Son—is the communicator. So Jesus' words from the cross were communication within the Godhead, God the Son addressing God the Father, not merely a human Jesus talking to Himself. Les also notes that God talks to Himself, and on the cross God did so in the sense of God speaking to God.