Vis-a-vis the communion of saints, Protestants often object that Christians who fall asleep in Christ are “dead” and basically disconnected from everyone else. Though they are not precise about it, the implication is that God keeps their souls in some sort of holding state until the bodily resurrection.
I’ve typically responded by arguing for the communion of saints from Luke 20:38, where Jesus, refuting the Sadduccees, said: “For he is not the God of the dead, but of the living: for all live to him.” Abraham, Isaac, and Jacob, Jesus informs them, are not “dead” but alive in God.
The broader point is that Christians, when they die, are not severed from Christ’s Mystical Body. They remain joined to it, and in communion with the other members. Today I read this passage from 2 Corinthians 5 that emphasizes this reality:
We know that while we are at home in the body, we are away from the Lord, for we walk by faith, not by sight.
We are of good courage, and we would rather be away from the body and at home with the Lord.
So whether we are at home or away, we make it our aim to please him.
Being “away from the body” means that intermediate state between bodily death and bodily resurrection. The souls of the just are in the presence of God during this time. (For more about death, judgment, and the fate of every person, see Catechism paragraphs 1005 and 1021, as well as this entire section.)
St. Paul says, incredibly, that we would rather be away from the body because we would be “at home with the Lord.”
So those who die in Christ do not “die” in the sense that they are separated from God, from Christ’s Mystical Body, or from other Christians. Rather, as the Catholic Church has always taught, not even death can separate us from God. Instead, it is the gateway to eternal life with Him.
May the souls of the faithful departed, by the mercy of God, rest in peace. Amen.