READ : 1 Peter 1:1-5
… chosen according to the foreknowledge of God the Father, through the sanctifying work of the Spirit, for obedience to Jesus Christ. (v. 2, NIV)
A Jehovah’s Witness who had knocked on my door challenged me in the course of our conversation to give a clear and concise definition of the Trinity. Here’s how I responded: The word trinity (“tri-unity”; three-in-one) refers to the biblically revealed truth that there is plurality within the unity of God’s nature (one God in three “persons”). The God unveiled in the Bible (and later described in the creeds of Christendom) is the one sovereign and majestic Lord. Historic Christianity thus affirms belief in one infinitely perfect, eternal, and personal God – the transcendent Creator and sovereign Sustainer of the universe. The Bible also reveals this one God as triune. He exists eternally and simultaneously as three distinct (though not separate) persons: Father, Son, and Holy Spirit.
All three persons in the Godhead share equally and completely the one divine nature, and are therefore the same God – coequal in attributes, nature, and glory. God has revealed himself as one in essence, but three in personhood. In terms of what God is (essence), God is one; in terms of who God is (personhood), God is three. God is therefore one “what” and three “whos.”
“Holy, Holy, Holy! Merciful and mighty! God in Three Persons, blessed Trinity.”