This claim is absolutely true. While there is a certain conundrum in the mysterious fact that the Son was somehow subject to The Father, as scripture indicates, Jesus is absolutely God in human form, who emptied Himself of his glory to dwell among us and who taught us how to live and who died for us; who rose again on the third day and who ascended into Heaven; who will one day return in glory. By the Holy Spirit, I know this for myself.
I believe that the accumulated statements concerning: (1) what the prophets said about God and the coming Messiah (2) what Christ said and did and (3) what the apostles and their companions declared about Him in the NT writings–all considered together–are best explained in terms of the Trinity.
The doctrine of the Trinity makes a clear distinction between, on one hand, the persons of the Father, Son, and Holy Spirit with their person-specific existence, roles, and actions and, on the other hand, their shared nature as God. None of them existed–or could have existed–apart from any of the others, and all have existed from eternity.
So, the claim that Jesus Christ is God is, as an aspect of the full revealed Word of God, necessarily true.