There are large number of Quran Verses and Hadiths of Prophet Saw which clearly mentions that dealing in Interest Riba is Haram. Allah Swt says in Quran "Allah has permitted trade and has forbidden usury". Allah Swt says in another Verse "That they took usury though they were forbidden and they devoured peoples wealth wrongfully". In another Verse Allah Swt says a person who deals in Interest Riba is actually doing War with Allah Swt. The Reason Allah Swt has made Interest Haram because it is harmful for poors and beneficial for a rich person. Due to Interest Richer continues to become rich while Poor becomes more Poor.
Now i come to my Topic that Is Working in Bank Halal or Haram??? According to Most of the Islamic Scholars Working a Interest Bases Bank Is totally Haram in Islam because Bank is an Institution which deals in Interest. While Working in Bank you are actually Dealing in Interest and Promoting it. While according to Some Scholars Such Job in Bank is allowed which is not directly connected to Interest Like Job of a Guard or Food Maker. Some Scholars says it is also Haram to do such Jobs. May Allah Swt help us all in Earning Money by Halal ways and avoiding the Haram.