Here are three examples from the New Testament:

1. Therefore go and make disciples of all nations, baptizing them in the name of the Father and the Son and the Holy Spirit… (Matthew 28:19)

Jesus ordered his disciples to baptize in the name of all three persons.

2. Now there are different gifts, but the same Spirit. And there are different ministries, but the same Lord. And there are different results, but the same God who produces all of them in everyone. (1 Corinthians 12:4-6)

Three separate words are used to refer to God in this verse:

Spirit – pneuma

Lord – kurios

God – theos

3. The grace of the Lord Jesus Christ and the love of God and the fellowship of the Holy Spirit be with you all. (2 Corinthians 13:14)

All three persons are named again.

“This insight was so new, so unexpected, so big, that it literally took the early church hundreds of years of dialoguing, thinking, worshipping, praying, and – yes – fighting over it, to find ways to talk about it that were acceptable to all (or to very nearly all) Christians.” (Christian Hofreiter)

Conclusion

I have not covered every argument there is nor did I cover any comprehensively in the interest of not losing you, the reader. But I think a classic Indian story will supply some perspective at the end of this discussion. You have probably heard it, but six blind men investigate an elephant. They touch various parts of the elephant and make six different assumptions, reliant on the various parts they touched: the elephant is like the trunk of a tree, a broom, a sieve, etc. Neither man was correct and they each perceived the animal differently. Even if they had a committee meeting afterward, they would not have been able to figure out how a tree, a broom, a sieve, and so on fit together. This is indicative of the Trinity if nothing else. We are not able to understand the Godhead properly or sufficiently.

Thus, I would like to close with Romans 11:33-36, because we must remember God is an infinite and perfect being who is responsible for creating the universe and everything in it. While we are merely finite, far from perfect beings trying to understand something we never will on this Earth.

“Oh, the depth of the riches and wisdom and knowledge of God! How unsearchable are his judgments and how inscrutable his ways! ‘For who has known the mind of the Lord, or who has been his counselor? Or who has given a gift to him that he might be repaid?’ For from him and through him and to him are all things. To him be glory forever. Amen.”