@otso @sinbach It is indeed very good because they can read the Bible and come to a knowledge of God. What can Psalm 45:6-7 mean other than that Jesus is not only a true man, but also God?
Your throne, O God, is forever and ever. The scepter of your kingdom is a scepter of uprightness; you have loved righteousness and hated wickedness. Therefore God, your God, has anointed you with the oil of gladness beyond your companions.
These verses are applied to Jesus, whose throne is forever, and who is anointed by God the Father, in Hebrews 1:8-9.
There's a nice article on the Old Testament basis of our understanding of the Trinity by Jews for Jesus,
https://jewsforjesus.org/learn/a-jewish-view-of-the-trinity-based-on-the-hebrew-scriptures/
Also Jesus said things that show he believed himself to be God, for example Matthew 26:63-65, where he said he would be seated at the right hand of God and coming on the clouds. Cloud riding was understood to be something gods, not humans did, so he was convicted of blasphemy (which was only untrue because he is God)
@otso No one can say "Jesus is Lord" except by the Holy Spirit (I Cor 12:3) and we are both saying "Jesus is Lord". Salvation is by knowing Jesus, not by the excellence of our theology (although wrong theology can get in the way of knowing Jesus).
The church's answer is one God in three persons. Does anybody really fully understand that? Probably not. Most simple explanations which give God three roles (the same man can be the son of his parents, the husband of his wife, and the father of his children) seem to fall into the heresy of modalism, where you only have one person.
But should we really expect such a complete understanding of God? Can we understand wave-particle duality in a clear way? We can recite the wave behavior of photons encountering slits and the particle behavior demonstrated by the photoelectric effect, but I at least can't say I understand it. And the seraphim flying around God's throne are said to see something new about Him every circuit.