One who acts without knowledge is like one who travels off the path; and the one who acts without knowledge corrupts more than he rectifies. So seek knowledge in a way that does not harm your worship, and seek to worship [Allâh] in a way that does not harm [your seeking of] knowledge. For verily, there were people (the Khawârij extremists) who sought to worship [Allâh] but abandoned knowledge until they attacked the Ummah of Muhammad – Allâh’s praise and peace be upon him – with their swords. But if they had sought knowledge, it would not have directed them to do what they did.
Source: http://www.sayingsofthesalaf.net/index.php/category/fitnah/#ixzz265z9LACh
