en_tn/2ti/02/11.md

This is a trustworthy saying

"These are words you can trust"

If we have died with him ... he cannot deny himself

This is most likely 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. (See: rc://en/ta/man/translate/writing-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.