"Man shall not live by bread alone, but by every word that proceedeth out of the mouth of God." (Matthew 4:4)
The Word of God is to your spirit as bread is to your body. When your body feeds on physical food, it produces a physical power called strength. When your spirit feeds on the spiritual food of the Word, it produces spiritual power called faith. And just as you can't eat one meal and then feed on the memory of it for several weeks, you can't just remember what the Word says and stay strong in faith. You have to read it. Even if you've read it a hundred times, you need to read it again.
Try this: Close your eyes and see yourself slicing a lemon. Now stick that lemon slice between your teeth and when I say, "Three," bite down on it so hard that the juice squirts into your mouth. One. Two. Three. Bite!
Chances are, you have such a vivid memory of what it's like to bite on a lemon that your mouth is watering right now. But let me ask you this, "Have you received any nourishment from that memory?" No.
Remembering the Word of God isn't enough. You must continually feed on what it says. Get it out and read it. Go to church and hear it preached.
One day, you'll read a familiar verse...a verse you've read thousands of times before...and suddenly God will give you the greatest revelation you've ever had. A completely fresh revelation from that old familiar verse! And it's likely to be exactly what you needed to know about your current situation.
Yes, you can feed on the Word that is on deposit in your spirit. But remember this: You can't get continued results if you don't spend time in prayer and in the Word of God allowing the Spirit to nourish you daily.
Don't try to live on the memory of your last spiritual meal. Replenish the force of faith within you. Feast on the Word of God today.