# This is a trustworthy saying
"These are words you can trust"
# If we have died with him, we will also live with him
This is most likely the beginning of a song or poem that Paul is quoting. If your language has a way of indicating that this is poetry, you could use it here. If not, you could translate this as regular prose rather than poetry.
# died with him
Paul uses this expression to mean that people share in Christ's death when they trust in him, deny their own wants, and obey him.