Now, let me pause a moment to say something very important: you will never go wrong believing the truth of the Word. The Lord DOES NOT LIE. He does not tease. He does not exaggerate. He is utterly truthful and utterly infallible and utterly faithful. If He promises, then you can be certain that you will get what He promises. If in doubt, err on the side of the Lord, not on the side of your own understanding.
Speaking of doubt, how does one with the “doubting disease” manage not to doubt the Lord’s promise? The verse says that if you do doubt then you will not get the promise because you are unstable. But what if you are praying for the very stability that you need? The answer is actually pretty simple: understand that this is the Lord. He promised and does not lie. If you doubt Him, then you are calling Him a liar. It is that simple.
So if doubts even try to sneak in, be stern with yourself and say “I am NOT going to call God a liar. Period.”. The devil will try to make you doubt, because this verse is powerful in your healing. This verse IS your healing. The Lord will give you wisdom to identify the weeds in your thinking, the errors of your ways. He will give you the wisdom to understand your behavior and to articulate the root of the problem. He will give you the ability to use every tool that He has for you to get rid of these disorders in the faith in this promise.
For me, the first test of my faith in this verse came almost immediately, even as I stood up from praying. I did not feel any wiser. Let me tell you that you will probably not feel any wiser at all. Why? Because this prayer is not for human wisdom—you will not automatically know everything from quantum theory to if the refrigerator light stays on when the door shuts.
No, this is the wisdom of the Lord. It is HIS wisdom, which will flow to you freely, but you do not become God. Much like the water coming out of the tap, it is there when you need it.
You will see, slowly, as you do not doubt in this verse, that things start changing. You will not be instantly cured of these disorders, but you will know how to use the tools that you are given. You might notice that you have a ready word for someone who needs it. You might notice that you have discernment. You might notice that the Bible becomes easier to understand. Like the slow light of dawn, you will notice a gradual brightening in your life.
Remember, however, that this is available if you do not doubt. Do not call the Lord a liar. Do not allow the enemy to accuse you into doubting.
Another area that you might be attacked is the “I don’t deserve it” attack. You are right, you do not. None of us do. We are all weak, sinful, and filthy. However, understand that the Lord was clear in His Word: He gives to EVERYONE LIBERALLY and WITHOUT REPROACH.