Romans 8:29-30

For whom he foreknew, he also predestined to be conformed to the image of his Son, that he might be the firstborn among many brothers. Whom he predestined, those he also called. Whom he called, those he also justified. Whom he justified, those he also glorified.

God knew what He wanted us to become before we were created. God has always loved you and has always had a special purpose for all of us as believers. So it is that all things work out for our good. Even when things are going wrong in this world, from God’s perspective, He is still working things out for us because that is our destiny.

This is all done because we are connected with Jesus, God’s Son. Notice that all of the things listed here are things that have already happened to Jesus. Jesus was called and
He died for us and justified us before God. Now, Jesus has been glorified and is with the Father. Even though we have not been glorified yet and still suffer here on earth, God sees us in Jesus and sees that we are glorified. This is our destiny and it is good for us to know about it and think about it as we go through this life.

Jesus was the firstborn in that He is the model that we will be following. He died and was resurrected and that is what God will also do for us.