The Holy Spirit
In Christian doctrine, the Trinity says that God exists in three parts:
- The Father: the omniscient being that created all things
- The Son: the physical form in which God came to Earth to witness to humans
- The Holy Spirit: God existing within a human that has accepted him as Lord
So, the Holy Spirit “lives in” humans that have accepted the existence of God, and that Jesus Christ was his physical manifestation on Earth.
From 1 Corinthians 6:19 (NIV):
Do you not know that your bodies are temples of the Holy Spirit, who is in you, whom you have received from God? You are not your own.
The Holy Spirit descended on the disciples on the 50th day after the crucifixion, as described in Acts 2:
When the day of Pentecost had come, they were all together in one place. And suddenly from heaven there came a sound like the rush of a violent wind, and it filled the entire house where they were sitting. Divided tongues, as of fire, appeared among them, and a tongue rested on each of them. All of them were filled with the Holy Spirit and began to speak in other languages, as the Spirit gave them ability.
This is the one of the main tenets of Christian faith – that God lives in each believer, as The Holy Spirit.
Interestingly, there is no explicit reference to the word “Trinity” in the Bible. From Wikipedia:
While the developed doctrine of the Trinity is not explicit in the books that constitute the New Testament, the New Testament possesses a triadic understanding of God and contains a number of Trinitarian formulas.
“Triadic understand” and “Trinitarian forumlas” refer to places in the Bible where it’s clear that Christ follower know about and explicit refer to the three parts of the Trinity, but the word “Trinity” is never explicitly used.
Outside of the Bible, the first appearance of Trinitarian thought appears in the First Epistle of Clement (approx. AD 70), the author writes:
Do we not have one God, and one Christ, and one gracious Spirit that has been poured out upon us, and one calling in Christ?
The first theologian to explicitly use the word “Trinity” is Theopolis of Antioch in the 2nd century:
In like manner also the three days which were before the luminaries, are types of the Trinity, of God, and His Word, and His wisdom.
Though that is not the current accepted usage and meaning of “Trinity,” as described above.
Why I Looked It Up
I didn’t actually “look this up,” but I did ask the question.
Growing up in the church for 50 years, I’m embarrassed to say that I never quite understood the Trinity. I knew what God was, of course, and I knew what Jesus was, but I always thought The Holy Spirit was just some vague way of referring to both.
I was in a Bible study discussion group, and I finally spoke up and asked someone to explain to me exactly what The Holy Spirit was. My question was answered by a high school freshmen in a way that suddenly made sense to me.
Subsequent research showed that he was accurate. I have no idea why no other explanation stuck, but here we are.