Well…some secular arguments have already been stated.
Sometimes, people commit suicide while severely depressed, and if they would wait it out, with medication and/or counseling, treatment, the depression might lift and life might, again, seem worth living.
Also, some problems, in their moment, may seem overwhelming, but often, when we make it through to the other side, we see it is possible to survive many of even some of the most difficult problems, be stronger for it.
Problems are often temporary, that there are often highs and lows, and there was one time I very badly wanted to commit suicide, (but obviously didn’t ). Anyway, at that time, the depression was quite bad, and I felt utterly hopeless and helpless. Then, it did begin to turn around. I had one very hard year, particularly, but after that, my life got comparatively easier. In other words, the difficulties didn’t go on forever and ever and ever, like they seemed.
When a person is distraught, the answers might be literally right in front of him, but sadly, due to the depression, many times he/she can´t see them. A lot of people maybe don´t realize in that moment in time they have a really choice, feel desperate, can only see one way out, but generally, it’s not the case.
I remember when I was divorcing, worrying I might go into bankruptcy, and to me, bankruptcy seemed like the end of the world. I talked to someone who had been through it, found out she survived it, and is actually okay, now.
What I dreaded…the bankruptcy, also never did come to pass after all! So, I had worried a lot over nothing!
It is harder, I think, to motivate an atheist to want to live under circumstances, using purely secular views. Even my ex-husband, who is an agnostic, said he thought I would be actually be able to handle more than he would, because I had my faith.