For years, I wondered about the meaning of the phrase "faith needs a doubt." I asked somebody about it once, and they explained that without a doubt to overcome, faith can not exist. In order to believe, it is necessary to have unbelief, and overcome it. Supposedly, the act of "overcoming" disbelief is an act of faith.
It sounds true, but it isn't. The presence of the disbelief is the problem. Having disbelief in your back pocket at all times, constantly there to overcome, is an indication of a complete absence of faith.
Faith does not need a doubt. Doubt needs a doubt.
Faith needs simply to believe.
The great part is that, if you lack faith and are aware you don't believe, all you have to do is ask God for more faith. He will give it to you!
"If any of you lack wisdom, let him ask of God, that giveth to all men liberally, and upbraideth not; and it shall be given him. But let him ask in faith, nothing wavering. For he that wavereth is like a wave of the sea driven with the wind and tossed. For let not that man think that he shall receive any thing of the Lord. A double minded man is unstable in all his ways." James 1:5-8
If you're asking God for something, anything, even to show Himself to you, but you don't believe in it, don't be surprised when nothing happens. According to these verses, nothing is going to happen. You will not receive anything from the Lord, including confirmation from Him that you have no faith.
Your doubt is all the confirmation of your faithlessness you will ever need.
In direct contrast, Hebrews 11:1 states, "Now faith is the substance of things hoped for, the evidence of things not seen." Faith is the forensic evidence of the invisible, the tangible proof of things hoped for; it doesn't require doubt to become activated.
So, from here on out, I have determined within myself to doubt nothing except my own doubts. If I have doubts, I will give them the treatment they deserve. I will no longer doubt my faith. I will only doubt my doubts.
Doubt needs a doubt.
Faith has no room for it.