29 Jesus replied, "You are in error because you do not know the Scriptures or the power of God. 30 At the resurrection people will neither marry nor be given in marriage; they will be like the angels in heaven. 31 But about the resurrection of the dead--have you not read what God said to you, 32 'I am the God of Abraham, the God of Isaac, and the God of Jacob'? He is not the God of the dead but of the living." 33 When the crowds heard this, they were astonished at his teaching.
-Matthew 22:29-33
Christians do.
At the resurrection, we shall all be alive. I’m not so sure about before that and I don’t believe in Purgatory so...
Catholics are Christian, they believe the entirety of the Faith taught us by Our Lord and the Apostoles He appointed and the successors to them.