whoever should happen to confess that Jesus is the Son of God, the God abides in him, and he in God (1 John 4:15).
Confession is a verbal agreement. God the Father stated Jesus is His Son when Jesus was immersed into His priestly service (Matthew 3:17). Sonship has nothing to do with birth, it relates to a position (Galatians 4:1). The verbal agreement that Jesus is the Son of God, is the consensus with God the Father that Jesus is God in the flesh (John 5:18). There is only one God (Deuteronomy 6:4). And God will not give His glory to anyone (Isaiah 42:8). Yet, this One Divine Being possesses three distinct Persons. Thus, believing that Jesus is God in the flesh is a fundamental belief of the Christian faith.
Jesus is not a created being, nor is He one of many. He is uniquely one of a kind (John 3:16). The declaration that Jesus is the Son of God is a verbal agreement that He is God (John 5:18). After spending three years with Jesus, just prior to His death and resurrection three days later, the Apostle Peter confessed that Jesus was the Messiah (Christ), the Son of God (Matthew 16:16). Jesus did not hide His deity, but He also did not demand a visible manifestation of His deity to always be visible to others at all times (Philippians 2:6).
Therefore, the one who verbally agrees with God the Father that Jesus is the Son of God has God abiding in him. And by confession, great is the mystery of godliness: God was manifested in flesh (1 Timothy 3:16).