The nature of Jesus can be explained by this passage from St Paul:
“Have this mind among yourselves, which is yours in Christ Jesus, who, though he was in the form of God, did not count equality with God a thing to be grasped, but emptied himself, by taking the form of a servant, being born in the likeness of men. And being found in human form, he humbled himself by becoming obedient to the point of death, even death on a cross. Therefore God has highly exalted him and bestowed on him the name that is above every name, so that at the name of Jesus every knee should bow, in heaven and on earth and under the earth, and every tongue confess that Jesus Christ is Lord, to the glory of God the Father.” Philippians 2:5-11
Jesus has always existed as “God’s word”. When Jesus was born of the Virgin Mary, this eternal thing called “the word” took on the form of a body. God is incomprehensible and cannot be seen without the seer dying. Therefore, in order to appear in human form, the word of God had to “empty himself”.
This emptying is why Jesus on earth did some apparently strange things during his time on Earth. For example, despite being God, he did not know the time of the day of judgement (despite being the judge). This is why he prayed to his Father and called his Father “My God”.
This stuff is not at all explicit in scripture, and that is precisely why the church’s magisterium is necessary. It does this tricky exegesis for us, with the wisdom of 2000 years of saints.