For everyone who asks receives; those who seek find; and to those who knock, the door will be opened. (NIV)

For everyone who keeps on asking receives; and he who keeps on seeking finds; and to him who keeps on knocking, [the door] will be opened. (AMP)

For every one that asketh receiveth; and he that seeketh findeth; and to him that knocketh it shall be opened. (KJV)