Is sexual thought sin or not??

Everyone in r/openchristian is all “sexual feelings aren’t sins” despite the one verse “every one that LOOKETH on a woman to lust after her hath committed adultery with her already IN HIS HEART”

This verse reveals to me that sinful thought is sin. Another one that backs this up is “if you are even angry with someone, you are subject to judgment.” To me, these both say that bad thoughts = sin.

I have very bad thoughts of violence, but if thoughts arent sin anymore whats the point? I feel like some people just say that because it’s hard for them to get rid of bad thoughts, so they say “as long as i dont actually do it, it’s fine”