What exactly is the Trinity? According to the New Bible Dictionary:
Three affirmations are central to the historic doctrine of the Trinity: 1. there is but one God; 2. the Father, the Son and the Spirit is each fully and eternally God; 3. the Father, the Son, and the Spirit is each a distinct person.
 Turner, M., & McFarlane, G. (1996). Trinity. In D. R. W. Wood, I. H. Marshall, A. R. Millard, J. I. Packer, & D. J. Wiseman (Eds.), New Bible dictionary (3rd ed., p. 1209). Leicester, England; Downers Grove, IL: InterVarsity Press.