Is not acting upon what is not understood from the Qur'an and Sunnah considered an innovation (bid'ah) or not?

One must strive to seek knowledge that illuminates the path and shows what pleases Allah, for knowledge distinguishes between truth and falsehood. Allah raises those who believe and those who have been given knowledge in ranks. The superiority of a scholar over a worshiper is like the superiority of a Prophet over the lowest among you. It is not permissible to cease performing an obligation under the pretext of not understanding a verse or hadith, for the paths of understanding are open and accessible, and one can ask the people of remembrance. The world is cursed except for the remembrance of Allah and what follows it, and a scholar or a student of knowledge. One must beware of the devil's ingressions and his steps.