Paul says in 1 Timothy 3:16, "And without controversy great is the MYSTERY of godliness: God was manifest in the flesh, justified in the Spirit, seen of angels, preached unto the Gentiles, believed on in the world, received up into glory"
Not only is the God of the Bible a Mystery, in every sense of the word. But, so is the Lord Jesus Christ, Eternally YHWH, but for our sakes took upon Himself the very nature of humans, sin excepted. Thereafter the God-Man, in One Person, Jesus Chirst. Some things that Jesus said and did, are true to His Human Nature, like He "grew in wisdom". He was tired, and hungry and had to eat food. Said that He did not "know" the time of His Second Coming. Yet, on the other hand, as Almighty God, He forgave sins, accepted Worship, claimed equality with the Father, walked on water, raised the dead, healed the sick. knew what was in man. How exactly did His Two Natures "Communicate", is a great Mystery indeed. How could Almighty God enter the womb of a woman, and be born as a human child? It would drive us mad to try to work this out, but to reject any of this, endangers our souls!