Suicide is a tough one, and while no sin (aside from blaspheming the spirit) is unforgivable, there is always the argument that a true Christian could not become overwhelmed by depression that they would commit suicide.
One of my friends that I grew up with decided to take his life a few years back, he was a professed christian, and I could see fruits in his life. However, even if he wasn't really saved, it makes no difference now. Heaven is going to be the same with or without him, all we can do is keep our hands to the work with what needs to be done here on earth.
I disagree with the whole no true Christian can take their own life... If you've never experienced a sliver of depression let alone other mental illnesses its best not to comment on them..
Anyway I remember in the bible Jesus sweating grape sized amounts of sweat asking for his cup to be taken away from him, angels had to strengthen him..and He was god (and also human) ...depression,anxiety,bipolar,schizophrenia or any other illness can bring you to your knees and push you to the edge ...
If you haven't experienced any of this...id much rather you just say Despite the turn of events god still loves the person who took their life..bc that's true... And your not trying to rack your brain to come up with an answer as to why it happened...nor are you spitting out insensitive one liners like ," god doesn't give u more than u can bear" ...
I feel people say that just to get people to shut up..bc they don't know how to deal with and help them through the emotions they're going through..
I find saying ," idk, by I'm here for you" to be much more comforting than apathetic one liners.
And one last thing just BC someone may suffer from a mental disorder doesn't mean they don't have faith for them to be healed... It just happens... God didnt heal everyone or redirect everyone in the bible...paul was a man of faith and still had a thorn in his side.. So to say that is extremely insulting...
God has a reason for everything he does.He doesn't take everything away.