Thanks, Kirill, for taking the time to record your reflections on this.

07:30 in the video is not expressed as clearly as was intended - thank you for drawing our attention to this. The point is that God needs to take the initiative and make himself known in order for us to get to know him. He is indeed all-knowing; we are not. We need God's revelation; the incarnation of God in Jesus is the most personal and intimate form of divine self-disclosure there has ever been. (Read John 1:1-18)

Christians believe in a triune God (Father, Son and Holy Spirit). The full doctrine of the Trinity is expressed mainly in the New Testament but there are hints of it in the Old Testament too. Both Old Testament and New Testament believers worshipped God, but through the incarnation and Jesus's teaching about himself in relation to the Father and the Holy Spirit, the New Testament believers knew more about the nature of the God they worshipped and who has made himself known in Jesus.

There is a difference between being created by God and being a Son of God. Adam was created by God, and in God's image, but because of the Fall (Genesis 3) neither he nor any of us are naturally children of God, because the relationship with God is broken. Through Jesus, God's only-begotten Son, who died for us, we are offered the possibility of becoming God's children (see John 1:12-13; Romans 8:29; John 3:3-5), being born again, and this is an essential prerequisite for being part of God's family and kingdom.

I hope this helps answer your questions. Thank you again for writing.