Q. I heard that if you want to be safe you should check your mezuzot. Is this true?
If you knowingly walk on the train tracks when a train is coming you put yourself at serious risk, even if you are wearing tzitzit and reciting Psalms.
Checking your mezuzot is no guarantee that a miracle will rescue you.
This does not mean that you should not do religious things, but don’t regard them as magic. Let them remind you of the religious teaching about taking good care of your life (Deut. 4:15 etc.).
Praying to be safe is also a good idea, but your prayer should not be selfish – not “God, protect me!” but “Please protect me – and all Your children!”