The Lord tells us to ask and to seek and to knock. Not because He does not know what we need but more for us to acknowledge our need before Him and to look to Him as our provider. But, if He knows what I need before I even ask Him, why do I need to ask, much less stand there beating on His door?
It is important, while waiting for the Lord to open the door, to learn the lesson He is teaching at the moment. Many times, for reasons known only to the Lord, there will be a delay in seeing that door open. But remember, you can only do what God has given you to do. When you have done all you are to do, then stand fast in the faith and trust God to open that door. What if you have knocked and the door is still not opening? Keep on knocking until the Lord does what He promised. Never give up on God; He never gives up on you!