What is the ruling on going to the mosque when there are those who practice Bidʻah (innovation) and forbid evil, and say "Taqabbal Allah" (May Allah accept) after the prayer?

Innovations (bid‘ah) that do not lead to the one committing them becoming a disbeliever do not prevent the worshipper from coming to the mosque. Rather, be keen to go to the mosque, advise those who innovate, teach them the Sunnah, and alert them to what contravenes it. If a mosque free from innovations is found, then going to it is more appropriate.