How could it be that Jesus, who was God (Jn. 1:1; 1 Tim. 3:16), and in whom are hidden all the treasures of wisdom and knowledge, increased in wisdom? (Col. 2:3)
God is a Spirit (Jn. 4:24). Jesus, as God, had existed as a Spirit forever.
When He came to the earth as Jesus, he was Lord at birth, but that was in His Spirit (Lk. 2:11). His Spirit didn’t have to grow or increase in wisdom but His physical body did.
The Lord could have done things differently, but He didn’t. Jesus came into this world in His physical body exactly as we did. He had to grow and learn.
He became just like us so that we could become just like Him (2 Cor. 5:21).
This is the great exchange. He became like us so that He could bear all our iniquities and become a mercy high priest for us (Heb. 2:14-18).
Christianity does not produce a changed life but an exchanged life. Christ does not reform us, but He transforms us through His union with us. In the same way that the Eternal Christ could come and inhabit the body of an infant and still retain all His deity, He now inhabits our bodies through the new birth in all His glory and power. Like Jesus, grow in your wisdom and understanding of who you now are in Christ.