The word "trinity" is not found in the Bible. But this does not mean that the concept is not taught there. The word "bible" is not found in the Bible either, but we use it anyway. Likewise, the words "omniscience," which means "all knowing," "omnipotence," which means "all powerful," and "omnipresence," which means "present everywhere," are not found in the Bible either. But we use these words to describe the attributes of God. So, to say that the Trinity isn't true because the word isn't in the Bible is an invalid argument.
Is there subordination in the Trinity?
There is, apparently, a subordination within the Trinity in regard to order but not substance or essence. We can see that the Father is first, the Son is second, and the Holy Spirit is third. The Father is not begotten, but the Son is (John 3:16). The Holy Spirit proceeds from the Father (John 5:26). The Father sent the Son (1 John 4:10). The Son and the Father send the Holy Spirit (John 14:26; 15:26). The Father creates (Isaiah 44:24), the Son redeems (Gal. 3:13), and the Holy Spirit sanctifies (Rom. 15:16).
This subordination of order does not mean that each of the members of the Godhead are not equal or divine. For example, we see that the Father sent the Son. But this does not mean that the Son is not equal to the Father in essence and divine nature. The Son is equal to the Father in his divinity, but inferior in his humanity. A wife is to be subject to her husband but this does not negate her humanity, essence, or equality. By further analogy, a king and his servant both share human nature. Yet, the king sends the servant to do his will. Jesus said, "For I have come down from heaven, not to do My own will, but the will of Him who sent Me" (John 6:38). Of course Jesus already is King, but the analogy shows that because someone is sent, it doesn't mean they are different than the one who sent him.
Critics of the Trinity will see this subordination as proof that the Trinity is false. They reason that if Jesus were truly God, then He would be completely equal to God the Father in all areas and would not, therefore, be subordinate to the Father in any way. But this objection is not logical. If we look at the analogy of the king and in the servant we certainly would not say that the servant was not human because he was sent. Being sent does not negate sameness in essence. Therefore, the fact that the Son is sent does not mean that He is not divine any more than when my wife sends me to get bread, I am not human.
Is this confusing?
Another important point about the Trinity is that it can be a difficult concept to grasp. But this does not necessitate an argument against its validity. On the contrary, the fact that it is difficult is an argument for its truth. The Bible is the self revelation of an infinite God. Therefore, we are bound to encounter concepts which are difficult to understand – especially when dealing with an incomprehensible God who exists in all places at all times. So, when we view descriptions and attributes of God manifested in the Father, the Son, and the Holy Spirit, we discover that a completely comprehensible and understandable explanation of God’s essence and nature is not possible. What we have, however, done is derive from the Scripture the truths that we can grasp and combine them into the doctrine we call The Trinity. The Trinity is, to a large extent, a mystery. After all, we are dealing with God Himself.
It is the way of the cults to reduce biblical truth to make God comprehensible and understandable by their minds. To this end, they subject God’s word to their own reasoning and end in error. The following verses are often used to demonstrate that in the doctrine of the Trinity is indeed biblical.
Matt. 28:18, Go therefore and make disciples of all the nations, baptizing them in the name of the Father and the Son and the Holy Spirit,