Please don’t tell born again Christians they are going to hell.
If a person believes that Jesus is the Lord of their life and they are trying to apply Christianity to their day to day walk, try to walk along side them. You may be the instrument that helps them soften toward Catholicism. They may have some crazy idea that Catholics believe something that you might correct one day. They just might have a question for you, about Mary, or statues, or saints, or confession to a priest. Be ready with an gentle answer, and smile. Be kind. Don’t give them a reason to dig in their heals and resist Catholicism today or in the future. Gentle rains on the hardened soil makes it ready for the seed.
Think of it as strategy, like a chess game. Not like hockey where you ram your opponent into the boards, trying to get the puck and score a goal. lol God knows that they may live to 80 and he wants them at a certain place when they are 70. Some projects can be long term (and I may be one of them! lol)