I find thinking about things such as Abortion, The Right to Die and other Human Rights a really interesting way to spend time when lost in thought.
For context, I am a Christian, a Member of The Church of Jesus Christ of Latter-day Saints (a Mormon).
I believe in personal agency, meaning that one is in charge of and owns their own body. I believe that how someone lives their life and what they do is none of my business. It's only my job to love others and treat them the way I would want to be treated. If someone wants to die, it is none of my business to deny those feelings and shut them down. Now, that doesn't mean I won't offer them my shoulder, I won't offer them love and kindness, it means that if there's nothing more I can do, then I must step back and support their decision. Continue to be kind to them and continue to love them.
Someone who wants to die shouldn't be denied kindness and love, but they should receive even more of it. They should receive everything that you can offer and even if they go through with their plans, this should still be given that love and respect, even in their memory.
I've even thought about this in a secular sense— removing religion from the equation and I still get the same answers in my heart. If someone has mental illness and wants to die, then why not let them? Isn't that natural selection? Isn't that science? Basic biology? If someone wants to die, that removes mental illness from the gene pool and thus benefits humanity.
In short, no matter how you look at it. Suicide is a fundamental human right and shouldn't be denied to those who want it.