The Mystery of the Trinity

There is no perfect analogy to explain both the reality and mystery of the Christian Trinity.  By the way, the term trinity is not found in the Bible.

The analogy of water helps make some key points.  Water is a substance that has different forms and functions.  As a substance, it is H2O in all three forms: gas, liquid and solid.  Each form has specific functions.  As a gas (vapor, clouds), water can be transported effortlessly by air currents for thousands of miles.  As a liquid, water can be drunk by humans, nourish plants, transport goods on its surface.  As a solid, water cools; again goods can be transported on its surface.

As substance, God is one God; this is a primary teaching of the OT.  In the OT, there are hints of a trinitarian God, but only the NT contains a full teaching on the Son and Spirit.

To humans, as we perceive it, this one God (substance), takes on three persons, each with specific functions.  God the Father remains in heaven, in overall charge of the creation.  God the Son become human (Incarnation)---born, eats, sleeps, tires and dies as a human.  God the Spirit guides, teaches truth, empowers humans.  Though the issues of substance and form entertain and sometimes confuse the philosopher/theologian, the practical side of the Trinity for humans is function.  There is a mystery in how the divine and human nature of the Son can coexist, the Scriptures do not speculate on how this happens.  They state the fact but then quickly move on to function, the purpose of the Incarnation.

Another analogy is that of a single human person who plays three distinct roles: husband, father, son.  He is husband to his wife, father to his son, and son to his mother.  One person, three functions.