I agree that respectfulness is important to any discussion in any topic, but it should also not impede honesty. There are certainly aspects of some major religions that deserve to be confronted like misogyny, homophobia and purposeful misinformation. When religion actively tries to impose itself on society (and it does that on regular basis), it warrants a pushback.

Having the feeling that you know something just inside yourself should not be a sufficient reason to believe it. We could all fall victims to delusions, false memories and hallucinations. It's like the stereotypical institutionalized mental patient that believes themselves to be Napoleon. That's why it's important to not just have faith in your sourceless internal knowledge fueling the "I just know" argument, but to compare notes with reality.

The protagonist of the movie contact does not need to rely solely on her own experiences. The device that she used to travel can be build again and can continue to be tested until there is more conclusive data. Even in the movie's fictional universe, she should not be 100% sure of the truthfulness of her own experience until there is more evidence.