'First born' in the Bible

And when He again brings the firstborn [highest-ranking Son] into the world, He says,“And all the angels of God are to worship Him.”

By faith he kept the Passover and the sprinkling of the blood [on the doorposts], so that the destroyer of the firstborn would not touch them (the firstborn of Israel).

and to the general assembly and assembly of the firstborn who are registered [as citizens] in heaven, and to God, who is Judge of all, and to the spirits of the righteous (the redeemed in heaven) who have been made perfect [bringing them to their final glory],