In the Christian faith, the Holy Trinity defines God as three persons: the Father, the Son (Jesus Christ), and the Holy Spirit; one God in three persons. The three persons are distinct, yet are one substance, essence or nature having a single divine nature.
The members of the Trinity are co-equal and co-eternal, one in essence, nature, power, action, and will. They cannot be separate from one another.
If you believe this, then this t-shirt is perfect for you.