If you are challenged to explain the Trinity, consider this. From all eternity, before material creation and time, God desired a communion of love. He therefore expressed Himself in a perfect Word. The Word God uttered beyond and outside of time was and remains His perfect self-expression, containing all that God is, perfectly possessing every characteristic of the Speaker: omniscience, omnipotence, truth, beauty and personhood. Thus, from all eternity there were always, in perfect unity, the God who spoke and the Word who was spoken, true God with and from true God, Begetter and Begotten, distinct Father and distinct Son having the same indivisible divine nature.