Famous is the story of the guy who, during a flood, is found in his home by rescuers in a boat looking for people to save. But he refuses to board because “I’ve been pious all my life and G^d will save me.” The water rises and he goes up a floor. A hovercraft spots him but he refuses again for the same reason. The water rises more and a helicopter finds him sitting on the roof. Repeat of his refusal. Water rises more and he drowns. Goes straight to Heaven (he really was very pious all his life) and indignantly and incredulously storms to the Heavenly Thrown. “I served You all my life most faithfully and You let me drown!” To which the Almighty replies softly: “Well, I did send you a boat, a hovercraft, and a helicopter.”
Jews are not allowed a prima vista to rely on a miracle. We must be partners with God. Only after we did all we could, we may (and must) give it over to Him. To leave it all to G^d is a sign of foolishness if not rebellion.
Therefore, people who congregate for prayers during a dangerous pandemic are not devout but ignorant at best or fools at worst.
And if they’re Jewish and refuse to heed doctors’ warnings, while there are Gentiles who do listen to the physicians, they commit the worst crime in the Jewish Book: a desecration of G^d’s Name.
Besides, they may testimony to be idol worshipers. How so? They seem to hold that we pray to make G^d happy. But He’s fine already. Idols must be placated and served. The real G^d created the whole world to serve us, do us a favor, be generous to us. When He’s demanding (to praise and obey Him) He only does so for our good. To be ungrateful is bad for us.