This isn’t a topic to raise lightly! It’s the Christian response to the most important question of all: “What is the nature of God?” The meaning can be summarized by three simple affirmative statements*:
- There is only one God
- The Father, Son, and Holy Spirit are each God.
- The Father, Son, and Holy Spirit are not the same.
(*From the excellent little book: The Trinity: How Not to be a Heretic by Stephen Bullivant.)
Now, the interesting thing about this definition is that everyone recognizes that these three statements present a logical problem – yet we still insist that all three are essential to an authentic Christian faith (see The ‘Christian Litmus Test’).
The word Trinity isn’t found in the Bible: it’s a word that first appears in Christian writings about 170 AD, and it would be several more centuries before the teaching was formally spelled out in the Ecumenical Christian Creeds. So did it take that time for the early Christians to invent this idea? By no means! Every aspect of the above definition is solidly supported in the Bible (both New and Old Testaments actually) but it took Christians a few centuries (and a lot of arguing) before they agreed on just how to express the full Biblical teaching without falling into some kind of error (heresy). The problem is that when God revealed His nature in the Bible He described a relationship that doesn’t resemble anything in human experience. Since this is God’s self-description, we don’t want to leave anything out, but that’s what people have often tried to do. We call those omissions Trinitarian Heresies!
The most obvious way to reconcile the above three statements is to eliminate the first, and simply assume there are three separate gods. Well, that won’t do at all! We call that polytheism, and it’s vehemently opposed by both the Old and New Testaments (e.g., Deuteronomy 6:4, James 2:19). No Jew, Christian, or Muslim can tolerate this heresy (though interestingly, it’s at the core of Mormon belief.)
A more subtle error reared its head in the early centuries of Christianity when some folks thought that the idea of a Triune God would make more sense if we dropped the third assertion – if we just think of one individual God who operates in three different ways or modes. In human terms, that makes a lot of sense: for example, the same person can be a father, a son, and a husband. However, the Bible describes the three persons of the Trinity as operating independently and even interacting with each other. For example, while Jesus was standing in the Jordan river at His baptism, the Father spoke and the Spirit descended (Mark 1:9-11). Jesus regularly prayed to the Father (Matthew 26:39) and He sent the Holy Spirit from the Father (John 15:26). The account of Pentecost (Acts 2) is clearly speaking of three separate ‘actors’ and explicitly connects them to Old Testament teaching. So the simple idea of “one individual God with three roles,” sensible though it sounds, clearly doesn’t express what the Bible describes.
The last heresy, called Arianism (named after Arian, a fourth century priest) tried to make sense of things by downplaying the second assertion – essentially assuming that only the Father was really God, and the Son and the Spirit were ‘godlike’ but lesser created beings. That seems implied when Jesus prays to the Father or ascribes special knowledge to Him (Matthew 24:36), and Arianism had a lot of supporters for a while (including today, in the form of Jehovah’s Witnesses). But based on many other scriptures, like John 1:1-5, Genesis 1:2, and Philippians 2:6, the church ultimately produced the Nicene Creed which insists that Father, Son, and Spirit are each fully God.
But does this really matter? Isn’t it all just hairsplitting and semantics? After all, if we have to invent words like Trinity, and give special meaning to words like person to state a concept that we can’t really understand, how important can it be? But Christians have agreed from the beginning that within these seemingly contradictory Biblical facts is held the most important and incredible truth of all: that Almighty God, the One Eternal and All-Powerful Lord-of-all-that-is-and-can-ever-be, voluntarily chose to take on human form and pay the price of our rebellion so that we might live eternally with Him. We struggle (and fail) to wrap our heads around it, but this is the ‘rock’ on which our faith is built.