On worship without sound knowledge

Imam Hasan al-Basari (d. 720), the sage/scholar of Islam, said:

He who worships without sound knowledge is no different from a person travelling without a sense of direction; for he who acts without knowledge ends up doing more harm than good. So pursue knowledge without being remiss in worship; and engage in worship without being remiss in the pursuit of knowledge. There were those in the past who devoted themselves exclusively to worship and shunned knowledge; they ended up unleashing their swords on the Ummah of Muhammad, may Allah’s blessings and peace be on him. Had they been armed with sound knowledge they would have not been so misguided in their actions."