I understand that it is a mortal sin to rash judge with certainty that someone is guilty of grave sin.
I am really struggling with this. Where I live most people (though catholic ) tend to go by secular traditions rather than church teaching in many areas e.g. contraception. In fact I had a lot of problems finding an NFP practitioner. If I make an assumption that for example somebody is using contraception am I committing a mortal sin since based on statistics the likelihood is that they are.
I know I shouldn’t be thinking about this and it is none of my business - I wish I could fill my mind with something more interesting but a thought comes into my mind and it’s difficult to argue against it.