God has presented Himself to mankind in His written word and He is described as Triune. This is one of the hardest concepts for finite man to comprehend. Some even think that it is a logical contradiction.
The Universe gives us a hint to understanding this. Paul states in (Rom. 1:20b that God can be understood from what has been made. That is His Universe. It’s components are Time, Space and Matter. Each of these components is a Trinity. One example of the three is Matter. It is solids, liquids and gases. All are three are distinct from each other. They exist simultaneously and at the same time share a common identification. All are Matter. The same analogy is true for the other two. Time = past, present and future. Space = height, depth and width. This is easily understood and accepted
by a person with an average level of education, but when it come to accepting that attribute of the one who made it all it seems to pose some difficulty for those of average education and more so for those of a higher level of education. Let us not forget that we humans are finite (limited) in our understanding and God is infinite. It is our nature to reject that which we do not readily understand and conclude that it cannot be. May I suggest that (I Cor. 4:4) may have something to do with it. It says; “The god of this age has blinded the minds of unbelievers, so that they cannot see the light of the gospel of the glory of Christ, who is the image of God.” Paul also stated in (Romans 1:20) that “men are without excuse”. God is God and if we humans could understand Him He would NOT be God. God declares this in (Isa.55:9ab) ” For as the heavens are higher than the earth, So are My ways higher than your ways”
God has Never required that we understand. Only that we Believe what He has said to us in His word. After believing it is to our advantage to apply it and enjoy His many blessings that have been made available to His children.