The commander "brought Paul down and made him stand before them. "

Paul was aware that some were Sadducees and some Pharisees,
so he called out before the Sanhedrin,
"My brothers, I am a Pharisee, the son of Pharisees;
I am on trial for hope in the resurrection of the dead."
When he said this,
a dispute broke out between the Pharisees and Sadducees,
and the group became divided.
For the Sadducees say that there is no resurrection
or angels or spirits,
while the Pharisees acknowledge all three.

-- Acts 22:30; 23:6-11

Belief in the resurrection of the dead has been an essential element of the Christian faith from its beginnings. "The confidence of Christians is the resurrection of the dead; believing this we live."

How can some of you say that there is no resurrection of the dead? But if there is no resurrection of the dead, then Christ has not been raised; if Christ has not been raised, then our preaching is in vain and your faith is in vain. . . . But in fact Christ has been raised from the dead, the first fruits of those who have fallen asleep.

-- CCC 991

Christ, "the first-born from the dead" (Col 1:18), is the principle of our own resurrection, even now by the justification of our souls (cf. Rom 6:4), and one day by the new life he will impart to our bodies (cf.: Rom 8:11).

-- CCC 658