Those who are constant doubters can enjoy neither here nor there. Such men are psychologically incapable of enjoying any situation, because the doubting tendency in them will poison all their experiences. He whose teeth have become septic must constantly poison the food that he is taking; so too those who have this tendency of doubting everything, will never be able to accommodate themselves to any situation, how perfect and just it might be.
In the Bhagavad Geeta Lord Krishna condemns such men of endless doubts, and points out their tragedy in life. The Lord says that such men who “doubt the Self” will not find any joy or happiness anywhere—”neither here nor in the hereafter.”
When through the practice of Karma yoga, we have learnt to renounce our attachments to the fruits-of-action, and yet to work on in perfect detachment—when every doubt in us regarding the Goal-of-life has been completely removed in our own inner experience of the nobler and the diviner in us—as a result of the above two, the ego comes to rediscover itself to be nothing other, than the Atman. Then the individual ego comes to live “poised in the Self as the Self”. When such an individual works, his actions can never bind him.
This being the wondrous result and the supreme profit that-‘true knowledge’ can give to the deluded, Krishna advises Arjuna to cut with the sword of knowledge the bonds of ignorance and “cleave asunder this doubt-of-the-Self lying in the heart.”

Doubts are but the shadows of your own mind’s dancings. Quieten the mind through prayer and realize that which is beyond all doubts.