Please click HERE for the Catholic explanation for why we use a crucifix instead of an empty cross.
I once had a good friend ask me this same question and then ask “Don’t Catholics know that Jesus rose from the dead? Jesus is not still on the cross.
My explanation was that every mass we celebrate is a sacrificial Remembrance of Christ’s death. And every Sunday is a celebration of His resurrection on the first day of the week–Sunday! So, yes we are well aware that Christ rose from the dead. But John saw the Lamb of God in Heaven looking like it had been slain…So even though the sacrifice happened in time once, it is an eternal sacrifice also. Therefore we commemorate this eternal sacrifice with a crucifix.
Also, Catholics take the scriptures very literally and have a theology of the redemption of suffering, not only Jesus’ but our own suffering is efficacious when joined to the cross of Christ. So, when we “offer up” our suffering in union with Christ’s and the crucifix aids our prayer and reminds us that we have not suffered as much as He. Meditation on His suffering helps us to bear our own suffering.
Now I rejoice in my sufferings for your sake, and in my flesh I do my share on behalf of His body, which is the church, in filling up what is lacking in Christ’s afflictions.