No child of God can be haughty about the Holy Trinity because no one discovered it or carefully reasoned it out it was revealed by God little by little and line by line here a little and there a little until it was clear enough for a child to see. God is one and God is Father, Son, and Holy Spirit one yet three one in glory, power, eternity, and knowledge yet three in persons. It is easy to understand but it is also wholly unlike anything in creation. What gives some trouble is their desire to "see" the Trinity, to grasp the concept and imagine what the concept "looks like". That is why so many have tried to give an analogy only to fail. Water as vapour, liquid, and solid is an analogy of modalism, a three leaf clover is an analogy of tritheism, Jehovah's witnesses teach arianism in their desire to "see God", and oneness Pentecostals teach modalism in their desire to "see God". None shall see him as he is until he reveals himself in the resurrection to the saved on the last day. The blessed saints in haven now see God yet their vision is not the blessed vision of resurrection eyes. As saint Paul said "Now I know only in part; then I will know fully, even as I have been fully known."
No one on Earth condemns but every one of the faithful judges the words and deeds of others to test them and see if they are of God. That is discernment. To test what is present and keep only what is good and holy and pure while rejecting everything that is corrupted.