What is a good innovation? What is wrong with acting on it?

All perfect praise be to Allaah, the Lord of the worlds. I testify that there is none worthy of worship except Allaah, and that Muhammad, sallallaahu ‘alayhi wa sallam, is His Slave and Messenger.

Good innovation, according to the scholars of Islamic jurisprudence, refers to an innovation that is founded on evidence from the Sharee‘ah that indicates its lawfulness. However, these scholars also mentioned that the righteous predecessors considered some innovations as good only from the linguistic perspective of view in Arabic, and not from a Sharee‘ah perspective because the word “Bid‘ah” (innovation) in the Arabic language means initiating an action that has not existed before so it may be described as good or bad according to the nature of the initiated action itself.

An example of this is the saying of ‘Umar when he saw people praying the night Ramadan prayer (Taraaweeh) -- something that they were not used to doing during the time of the Prophet, sallallaahu ‘alayhi wa sallam -- and remarked, "What a good innovation!” Thus, some innovations are good merely from this perspective.

And Allaah Knows best.