Doubt and denial seem to be an important part of spiritual development. Tales are told in most if not all religious traditions about those who deny, and who, other than Judas, lived to recant. Look also at stories of Christian and other martyrs, of Sai Baba, HPB, et al. Where there is a Light Bearer there must be those trying to drag us back into the darkness where they are more comfortable. Where there is purity, folks will sling mud. It seems to be one of the basic and undeniable, unavoidable rules of the universe. Like Yin & Yang, like there can be no up without a down to compare it to. Where there are those trying, we will find those falling short. “Seek & you will find”? Sure. But only if you are willing to get lost so many times that you have felt like giving up. “Knock & it shall be opened”? Maybe. But sometimes it will be the wrong door.
But the light is in there; and someday, you will get all the way home, only to realize that even when failing, even in your very darkness moments, you actually had been there all the time.