firstborn

All things exists in Him

He is the image of the invisible God, the firstborn of all creation.

For by Him all things are created, both in the heavens and on earth, visible and invisible, whether thrones or dominions or rulers or authorities-all things have been created through Him and for Him.

He is before all things, and in Him all things hold together.

Colossians 1:15-17 (NASB)

Mount Zion

But you have come to Mount Zion and to the city of the living God, the heavenly Jerusalem, to an innumerable company of angels, to the general assembly and church of the firstborn who are registered in heaven, to God the judge of all, to the spirits of just men made perfect, to Jesus the Mediator of the new covenant, and to the blood of sprinkling that speaks better things than that of Abel.
— Hebrews 12:22-24 (NKJV)