Thank-you for asking a question that puzzles many. How indeed could Jesus be pleading to God for us if he is already God? Is this a great deception on his part? Or is this premise incorrect?
There are some scriptures if taken out of context that can lead sincere students of the Bible to conclude that Jesus is God. For example, John 10:30 reads, “I and my Father are one.” Some inaccurately conclude that Jesus was saying he was the God of the Universe.
However, in John 17:21, Jesus pleads with his Father on behalf of his apostles. “That they all may be one, as You, Father, are in Me, and I in You; that they also may be one in Us, that the world may believe that You sent Me. And the glory which You gave Me I have given them, that they may be one just as We are one:” – John 17:21-22 NKJV
Obviously, our Lord was not pleading that his apostles be literally one in the same person. Jesus was saying that he and God the father were one and in harmony respecting purpose and holy character.
Another example is Jesus’ encounter with Mary outside of his tomb after his resurrection. “Jesus said to her, ‘Do not cling to Me, for I have not yet ascended to My Father; but go to My brethren and say to them, “I am ascending to My Father and your Father, and to My God and your God.”’” – John 20:17 (NKJV) The obvious question is if Jesus is God, how could he have a god?
Lastly, the Apostle Paul wrote that when Jesus’ work is fully complete and his reign concludes, then he himself will still be under his Father’s authority. “Now when all things are made subject to Him, then the Son Himself will also be subject to Him who put all things under Him, that God may be all in all.” – 1 Corinthians 15:28 NKJV
Space prevents us from responding to all arguments on this subject. Plainly, Jesus is not God but just who he said he was – the Son of God. Jesus was created by God as seen in Revelation. “And to the angel of the church of the Laodiceans write, ‘These things says the Amen, the Faithful and True Witness, the Beginning of the creation of God:’” – Revelation 3:14 NKJV Jesus and God are separate and distinct beings.
Finally, “pleading” is Strong’s word G1793 and it is usually translated to “make intercession” or to “intercede” for us. Jesus purchased us with his blood and thereby paid for our sins. Justice has been satisfied. Jesus pleading sounds like he is emotionally entreating, begging God to forgive us. But when we pray through Jesus, God forgives our sins because justice has been paid. (1 John 1:9)