I think the one thing we always must do is worship God, and we can do this almost any time under almost any circumstances.
We can remember that God is the creator of all things, infinite in time and space, was here before anything was, and will be here after all is gone. Even a materialist can do this. Since God is the ultimate power, creator, and controller, we can remember he is the only and final judge of all things, and that his is the only real will, and the only will that matters.
We can also remember our hope in Jesus, and whatever degree of belief we have. We can remember our proper relationship with God, which is that he has the final say in all things- not us, not our friends and loved ones, but also not our enemies or his enemies.
Job, after all, fell down and worshipped God. It didn’t mean he like what was happening to him, it only meant that in his worst moment, he remembered that God controls everything, that everything was in the hands of God.
We don’t have to like it, we don’t have to understand it, but we can always acknowledge it.