Door To Door

Mark 1:9-11 ESV
9 In those days Jesus came from Nazareth of Galilee and was baptized by John in the Jordan. 10 And when he came up out of the water, immediately he saw the heavens being torn open and the Spirit descending on him like a dove. 11 And a voice came from heaven, “You are my beloved Son; with you I am well pleased. ” Out of Nazareth, out of the Israelites, in the fullness of time, the heavens are opened as the Son begins the work He has come to do. He has opened the gates of heaven.
Later, when He is given over to death, the veil in the temple is torn providing access to God.  His work is accomplished.  No one is able to close what He has opened, or open what He has closed, for He is the gate and the way.
Jesus sees heaven opened, the Spirit descend, and hears the Father speak.
No longer does the Spirit only hover over the water, but comes down and remains.
The Father gives witness. It doesn't say anyone else saw or heard. I think this speaks to the internal evidence of the eternal truth. This is the witness of the Father.
It is the same with us. The Holy Spirit testifies to our spirit and is revealed in our lives.
We have the power to open or close a door as well, the one to our heart. Jesus has opened the heavens and issued the invitation. He goes from door to door and knocks. We decide whether to open or not. No one else can do so.