SUPPORT FOR THE TRINITY
There is some vague support for the Trinity in the New Testament, but not strong support. So my view is that Jesus was okay with "believing" in the "Trinity", but didn't consider it important. I think he was probably okay with it, because he knew the cataclysmic history of Earth and the traumas that ancient peoples went through, which shaped their world views, and he respected the good aspects of those world views. See Saturn Theory below. God the Father/Creator, God the Son/Redeemer and God the Holy Spirit/Wisdom are all good concepts. But Unity is what's important, not division. AI can help you find evidence in the Bible for the Trinity, if you like, but I want to emphasize here that it's not important, except as it helps to support the understanding of the importance of Unity.
JESUS DIDN'T OUTRIGHT SAY HE WAS GOD.
In the Gospel of Mark, Jesus affirms the theology of a non-Trinitarian Jewish scribe in Mark 12:28-34. In this passage, a scribe asks Jesus which commandment is the most important. Jesus responds by quoting the Shema from Deuteronomy 6:4-5, which emphasizes the oneness of God: "Hear, O Israel: The Lord our God, the Lord is one." The scribe agrees with Jesus, affirming that there is only one God, and Jesus commends him for his understanding.
Mark 13:32; Matthew 24:36: "But about that day or hour no one knows, not even the angels in heaven, nor the Son, but only the Father."
Luke 2:52: "And Jesus grew in wisdom and stature, and in favor with God and man." (This implies that Jesus, as a child, grew in knowledge over time.)
John 5:19: "Jesus gave them this answer: 'Very truly I tell you, the Son can do nothing by himself; he can do only what he sees his Father doing, because whatever the Father does the Son also does.'"
John 5:30: "By myself I can do nothing; I judge only as I hear, and my judgment is just, for I seek not to please myself but him who sent me."
John 8:28: "So Jesus said, 'When you have lifted up the Son of Man, then you will know that I am he and that I do nothing on my own but speak just what the Father has taught me.'"
John 14:10: "Don't you believe that I am in the Father, and that the Father is in me? The words I say to you I do not speak on my own authority. Rather, it is the Father, living in me, who is doing his work."
Two verses (in John and Peter) say Jesus is our example. Jesus said, "Take up your cross and follow me" (Matthew 16:24, Mark 8:34, Luke 9:23). At that time the cross represented hardship, persecution, and even death, so he was telling them to follow his example, which they apparently ultimately did. And we're all to follow his example too. In John 14:12, Jesus said to His disciples: "Very truly I tell you, whoever believes in me will do the works I have been doing, and they will do even greater things than these, because I am going to the Father." And they did do greater works in some cases, such as converting many people beyond Israel. Jesus had 50,000 angels at his command, who apparently performed his miracles.
ANCIENT TRINITIES
Several ancient religions had concepts of trinity or triads before Christianity. Here are a few examples:
Ancient Egypt: The Egyptian pantheon included several triads, such as Osiris, Isis, and Horus. This triads represented different aspects of the divine and were worshipped as a unified whole. Osiris (God of the afterlife) has some similarities to the Father, symbolizing authority and continuity of life. Horus (God of kingship and protection) can be seen as somewhat analogous to the Son (Jesus), representing kingship and divine power. Isis, revered as the goddess of magic, motherhood, and fertility, encompassed the life-giving breath and protective qualities, drawing a parallel to the concept of spirit in her ability to infuse life and wield divine power.
Babylonian Religion: The Babylonians recognized a trinity in their mythology, often depicted with gods having three heads or forms. This symbolized the unity of three divine aspects. The Babylonian trinity often referred to the composite god Anu, Enlil, and Ea/Enki. These three gods represented different aspects of the cosmos: Anu was the god of the sky (the Father?), Enlil was the god of the earth (the Son?), and Ea was the god of water (water symbolizes Spirit).
Hinduism: The Trimurti consists of Brahma (the creator [Father?]), Vishnu (the preserver [Son?]), and Shiva (the destroyer [Spirit?]). These three deities represent different aspects of the divine and the cyclical nature of the universe.
Buddhism: The Triple Gem or Three Jewels includes the Buddha (the enlightened teacher [Father?]), Dharma (the teachings [Spirit?]), and Sangha (the community of followers [Son?]). This trinity guides practitioners towards enlightenment and liberation.
Chinese Folk Religion: The Three Pure Ones are the highest deities in Taoism, representing the three primal energies of the universe: The Jade Pure One (Yuqing [Son?]), The Supreme Pure One (Shangqing [Spirit?]), and The Grand Pure One (Taiqing [Father?]).
Greek Mythology: The Greek goddess Hecate is often depicted in triplicate, representing different aspects of her divine power. Additionally, the Moirai (Fates) and the Charites (Graces) are examples of triads in Greek mythology2.
Roman Religion: Diana was revered as Diana Triformis, embodying three aspects—the hunt, the moon (Diana Lucifera), and the underworld—forming a divine triad with Egeria and Virbius, emphasizing her roles in childbirth, nature, and wilderness. The Capitoline Triad in Roman religion included Jupiter (the king of the gods), Juno (the goddess of marriage and childbirth), and Minerva (the goddess of wisdom and strategic warfare), representing the core of Roman state worship.
SATURN THEORY
Saturn Theorists found that ancient rock art and ancient documents very likely indicated that Saturn, Venus and Mars were close to Earth, in a line, so that they looked like concentric circles (I've heard some Christians use 3 concentric circles to represent the body, spirit and soul, from outer to inner. I think it ultimately came from cultural memory of the ancient Saturn Configuration of planets close to Earth. I have a substack on Cataclysmic Earth History and an online book, Ancient Myths Are Earth History). So I think it's likely that the Trinity came from the appearance of those 3 planets close to Earth in front of each other (Saturn/Father behind Venus/Spirit behind Mars/Son - The Book of Revelation uses Mars to symbolize Jesus, or the Christ child, so that’s additional evidence). And I think Jesus knew that and knew that we would eventually make that discovery and in the mean time he and/or the apostles wanted us to have good concepts of the Trinity for our inspiration.
ISRAELITES
In early Israelite and Hebrew belief, God was primarily understood in terms of three key aspects: Creator: God as the creator of the universe and everything within it, as described in the Book of Genesis. Lawgiver: God as the giver of the Torah and the laws that guide moral and ethical behavior. Redeemer: God as the deliverer and savior of the Israelites, particularly in the context of the Exodus from Egypt. These aspects highlight God's roles in creation, guidance, and salvation, reflecting the central themes of their religious beliefs. So it's obvious how the creator aspect could become God the Father, the Lawgiver aspect could become God the Holy Spirit (Paul said to follow the spirit of the law, not the letter of the law), and the Redeemer could become God the Son.
NON-TRINITARIAN CHRISTIANS
Several Christian denominations reject the doctrine of the Trinity. Some of the most notable ones include:
Jehovah's Witnesses: They believe that Jehovah is the one true God, Jesus is His first creation, and the Holy Spirit is an impersonal force, not a person.
The Church of Jesus Christ of Latter-day Saints (Mormons): They believe in a Godhead consisting of three separate beings: God the Father, Jesus Christ, and the Holy Spirit, who are united in purpose but not in substance.
Oneness Pentecostals: They reject the Trinity and believe that God is a single person who manifests Himself in different modes, rather than three distinct persons.
Christadelphians: They believe that Jesus is the Son of God but not God Himself, and they view the Holy Spirit as God's power or energy, not a person.
Christian Science: They view God as an all-powerful, all-good, and all-knowing Mind, and Jesus as a spiritual healer, but they do not adhere to the traditional concept of the Trinity.
QUAKERS
I don't care for JW or LDS etc, but I favor Quaker ideas quite a bit. They believe in seeking Direct experience of the divine, often referred to as the "inner light" or "Holy Spirit". They reject creeds and formal doctrines, including strict definitions of the Trinity. They believe in continuing revelation and personal responsibility for understanding faith. So they recognize that Unity is more important than conflict, and it was Quakers who began the development of the Unity method, called Sociocracy, which I discussed recently. By the way, the official name of Quakerism is The Society of Friends or The Religious Society of Friends.
VIDEO
The following video says a Jewish philosopher, Philo of Alexandria, was largely responsible for the doctrine of the trinity in Christianity. He apparently got the idea partly from Greek thought, partly from Judaism and partly from John 1:1-14: “In the beginning was the Word, and the Word was with God, and the Word was God. He was with God in the beginning. Through him all things were made; without him nothing was made that has been made. …” Sounds like John was a philosopher too. I prefer to think of Jesus as someone, whether angelic or mortal, who was one with God, i.e. was united with God’s will and so he did God’s will, instead of his own. And we’re meant to follow his example. As we do so, God’s power will express through us as it did/does through Jesus.