Definitive means full and complete, no human being has the mental capacity to fully and completely comprehend the infinite God.
God is our Father because He created us and loves us, His love is perfect. The Son is His representative that is the exact representation of God's love and righteousness as well as the epitome of how we should live a loving and righteous life. The Holy Spirit is the power of God that enables us to live the kind of life that is loving and righteous. The Holy Spirit is our teacher, the power that makes us conscience of sin, comforter, and who seals us with God's seal of redemption.
"To do or die" means we are to live in total obedience to God or suffer the consequences of eternal spiritual death. The Son's sacrifice is our appeal to God's love and by worshipping the Father through the Son, He (the Son) becomes our mediator and intercessor with the Father.
We are told in the Bible God's purpose and how to live according to His purpose, but as I posted no human being can give us a definitive answer to who God is since our finite minds are incapable of grasping all the complexities of an infinite God.