How can there be three personalities and only one God?  The doctrine of the trinity is a part of what it means to be orthodox Christian in your beliefs.

The doctrine of the Trinity is the doctrine that gets people in the most trouble throughout church history.  For hundreds of years, people have stumbled over the relationship between Jesus and God the Father.  The debates between Arius and Athanasius over the nature of the Trinity brought together the first ever council of bishops, the Council of Nicaea in A.D. 325.  Arius taught that Jesus was derived from God, but not God Himself, while Athanasius defended the traditional view that Jesus and God the Father are of one essence.  The council decided in favor of the traditional view, but the arguments within the church continued for several decades.  It was finally settled in A.D. 381 at the Council of Constantinople, where the Arian heresy was put to rest.

Two hundred years later, around the time of the Third Synod of Toledo in 589, the Nicene Creed affirming the divinity of Jesus, which had also been expanded at the Council of Constantinople, was changed regarding the place of the Holy Spirit.  The phrase, "and the son," was added so that it now read that the Holy Spirit proceeds from the Father and the Son, instead of just from the Father.  This change contributed to the break in 1054 between the western church, which became the Roman Catholic Church, and the eastern church, which became the Greek Orthodox Church.  The disagreements over the nature of the Trinity contributed to a schism within the church that persists even today.

Modern Christian cults fall at this same point.  One of the most characteristic marks of Christian cults is that they deny Jesus is the eternal Son of God.  But orthodoxy is not a new interpretation.  It is the historic and true teaching of scripture on key, essential issues.  Orthodoxy says that Jesus is God in the flesh and that the Holy Spirit is also God Himself.  This is the nature of the Trinity.

The doctrine of the Trinity is unique to Christianity.  Christianity is not unitarian and it is not polytheistic.  How do we reconcile these two things?  Does the Christian faith demand a belief that cannot be understood?  No.  It can be understood, and we do understand it.

We often think we don't understand the Trinity because we've been told we don't understand it.  But how much do we have to know before we can say we understand it?  Do we need exhaustive and total knowledge of all details?  Do we need exhaustive and total knowledge of how electricity is wired into our homes to understand that electricity is in our homes?

Of course not, and it is the same principle in play with the doctrine of the Trinity.  We may not know every detail or understand everything there is to know about the Trinity, but we do know something.  As we come to understand scripture, we come to understand the Trinity.  If we can understand what Peter, Paul, and James wrote, then we can understand what they say about the Trinity.

If you don't understand the Trinity, then you don't understand Christianity.  The Trinity is the essence of Christianity.  It is not the greatest burden of our theology, but what makes it true and understandable.  Look not to all the controversies surrounding the Trinity, but instead look to what the Bible says about the Trinity.

First, Who is God?  God is the source of all things.  He spoke all things into existence.  In the beginning,