If Jesus never sinned and was fully God then how do we understand the scripture that states he 'increased in wisdom', 'became perfect', and 'learned obedience'?
Luke 2: 52
And Jesus increased in wisdom and in stature[a] and in favor with God and man.
For it was fitting that he, for whom and by whom all things exist, in bringing many sons to glory, should make the founder of their salvation perfect through suffering.
Although he was a son, he learned obedience through what he suffered. And being made perfect, he became the source of eternal salvation to all who obey him,
We see that the same author (in Hebrews) himself says that Jesus is already perfect.
For we do not have a high priest who is unable to sympathize with our weaknesses, but one who in every respect has been tempted as we are, yet without sin.
For it was indeed fitting that we should have such a high priest, holy, innocent, unstained, separated from sinners, and exalted above the heavens.
how much more will the blood of Christ, who through the eternal Spirit offered himself without blemish to God, purify our[a] conscience from dead works to serve the living God.