Sri Chinmoy: Unfortunately, we cannot use the word "permanent" until the end of our spiritual journey. Some spiritual Masters are so sincere that they have told us that doubt remained with them until the last. Even one second before God-realisation they still had doubt. Again, some sincere seekers have no doubt, even from the very beginning. That doesn't mean that they are far better than the spiritual Masters. No. Imperfection in the form of doubt or something else was inside those great spiritual Masters, and eventually they conquered it.
There are two ways to conquer doubt. When doubt or other negative forces enter into you, you can take it as a monkey which is constantly bothering you. You are praying and meditating, and here a monkey is constantly bothering you. You let the monkey go on and on, because you are patient. There is a competition between your patience and the monkey's mischievous pranks. Just because you are a seeker, you are bound to have more patience than someone who is not aspiring. The monkey is not aspiring, so the monkey's patience can never equal your patience. In this world, as we have an ego, the monkey also has a form of ego. Only you don't see it. If you are not paying any attention to it, the monkey will eventually feel that it is beneath his dignity to bother you again and again. Patience has such capacity to dissolve wrong forces. If you have the capacity to ignore or to constantly reject the negative forces, then they can never win.
There is another way. If doubt enters, you have to think of the antidote for doubt, which is faith. If doubt is entering into your mind, immediately utter the word "faith" and have faith in yourself. Just say, "I am God's daughter; so how can I doubt myself, how can I doubt others, how can I doubt God?" God has become God not by doubting me or by doubting you or by doubting somebody else. He has become God by loving, by becoming one. And oneness comes only from progressive qualities like faith. So this is the evolving or progressive way to conquer doubt.
Doubt is an undivine force. I call it a slow poison. Doubt is our worst enemy in the spiritual life. Today I doubt myself, tomorrow I doubt God, the day after tomorrow I doubt the whole world. If I doubt God, nothing happens; God remains as perfect as ever. If I doubt some other individual, that person remains the same. But when I doubt myself I am ruined. I can't go even one inch forward. So the best thing is not to doubt oneself, not to doubt others and not to doubt God.