Yes very much so, Christians should live their lives at all times (most of us fail miserably at this:(, and then even during trials God's peace (Heart knowledge) will show in thier lives. It will be apparent to people watching and hopefully they might ask where your peace comes from. This is my understanding of being a witness for Jesus.
Becky
Would there be any benefit to them seing RCs say things like "you don't get to go to heaven just because you go to mass every week" or "you can't get in by being a 'good' person", "You can't earn your way to Heaven" "Catholics whould read their bibles and know them" ?
Then perhaps this is the way out of your impasse. It's the only one I can think of so far. Do you have others that have possibility?