Ok.
Are the dead believers, who are alive, in the Body of Christ?
Another good question.
I always thought of the Body of Christ being the church on earth. The body of believers within the church. The believers in heaven are face to face with Jesus Christ.
Dead believers are in a different category, no longer needing to walk by faith as Christians on earth must.
2 Cr 5:7 (For we walk by faith, not by sight:)
1Cr 13:12 For now we see through a glass, darkly; but then face to face: now I know in part; but then shall I know even as also I am known.