Question in response:
How can anyone worship a god who is perfectly understandable?
What do you think is wrong about the Trinity?
Quick Answer:
We never assert that we believe both in one and three gods, or one person and three persons. We believe in oneness in respect to being and Trinity in respect to persons. This may not be fully comprehensible, but it is not contradictory.
Our universe is filled with examples of a plurality within a unity. There are many examples in life (light, space, time, triangle, human body) and Scripture (marriage, nation, the tabernacle) of a plurality within a unity. It would make sense that this truth about our universe be deeply rooted in the creator of the universe.
If we could understand everything about the nature of God then either we would be God or we would have created a god in our own image which would not be a god worthy of our worship.
More Details:
If Christianity was man made then there certainly would have never been any concept like the Trinity in it. On the surface it seems so obviously contradictory. The Bible clearly asserts however that God is one but that within the oneness of God are three distinct persons.
It is interesting that if you really think about the nature of this world there are two undeniable realities. First, is the idea of unity and oneness. We experience unity with other people, animals, nature. But we also experience our own individuality – we are all unique from one another. I have my own thoughts, feeling and choices. These are two unmistakable realities about this universe – individuality and unity.
So, I ask you what kind of God made this world? The pantheistic god (god is everything) of eastern religions makes no sense of the existence of individuals. The strict monotheism of Islam and the cults does not make much sense of the unity and oneness in the universe. But, this strange and unusual concept of the Trinity makes perfect sense of these two unmistakable realities because in the very nature of God we have three distinct person who are one essence. (Ravi Zacharias, develops this argument in Can Man Live Without God? )
Concerning: What is the Trinity?
A. God is One. Read Deut. 6:4; 1 Cor. 8:4.
B. God is Three Persons. Read Gen. 1:26; Zech. 7:12; Matt. 28:29; Rev. 1:8; 22:13.
Summary: God is a unitary essence consisting of three co-equal persons.
Concerning Jesus saying “The Father is greater than I (Jn. 14:28)?”
When dealing with issues about God, because He is triune, we need to distinguish whether the question or issue is related to God’s essence, or the divine persons in their distinctive interpersonal relationships and/or their distinctive but harmonious ministries and functions in space and time. This issue is referring to Jesus’ functional self denial, not in reference to his essence. There is a way that the Father was greater than Jesus functionally.