What happens when a believer in Christ dies?

What happens when a believer dies? Do we stay in the ground? Or do we step into a glorious new world?

Psalm 116:15 Precious in the sight of the LORD is the death of his saints.

What "sleeps" in the grave are ONLY our bodies (which will be raised at the Rapture). Our (Christian's) spirits and souls go immediately to heaven upon the death of the body.

2 Corinthians 5:8 We are confident, I say, and willing rather to be absent from the body, and to be present with the Lord.

To die is to "gain" for the Christian. How can we gain if we are asleep in the grave with no awareness of what's happening (as some teach)?

Philippians 1:21 For to me to live is Christ, and to die is gain.