Man is made in the similitude, likeness, of God, but that does not make all men God's children,
as all men are made by the Creator, but Christians are born by the Creator, so only Christians are children of His.
I think the word 'born' is relevant here. Like who is born by God
You won't find a verse that says the unsaved are born of God again.
Those born according to the flesh are not the children of God, you just cannot get around that TRUTH, but people dispute with God all the time. over what He says.
NKJV
With it we bless our God and Father, and with it we curse men, who have been made in the similitude of God.
KJ21
Therewith we bless God, even the Father, and therewith we curse men, who are made in the similitude of God.
ASV
Therewith bless we the Lord and Father; and therewith curse we men, who are made after the likeness of God:
AMP
With it we bless our Lord and Father, and with it we curse men, who have been made in the likeness of God.