We are alive; it is up to us to decide what that means.
I would have to agree. There is no single purpose, but billions of purposes. Multiple purposes for each life, perhaps.
As a general rule, when someone moves discussion towards controversial topics, common viewpoints and general consensus thinking, I convince myself it's not as black and white as the other person implies, then logic my way through it.
Seriously. I do it multiple times a day. Every day. Good habit.