Is it permissible to say "Yarhamukallah" (may Allah have mercy on you) to someone who doesn't pray, if he sneezes?

It is permissible to say "Yarhamukallah" (may Allah have mercy on you) to one who sneezes and praises Allah, even if he neglects prayer out of laziness, as long as he acknowledges its obligation. This is because, according to the majority of scholars, one who neglects prayer out of laziness is not judged to be an disbeliever, even though he has committed a grave sin. Therefore, it is permissible to supplicate for mercy for him, especially after he has praised Allah.