Bhagavad Gita Verse 4.40

विवेकहीन और श्रद्धारहित संशययुक्त मनुष्य परमार्थसे अवश्य भ्रष्ट हो जाता है। ऐसे संशययुक्त मनुष्यके लिये न यह लोक है, न परलोक है और न सुख ही है|

If a person is ignorant of the Knowledge of God, the person who lacks faith in God and the one who is full of doubts in his own self, will undoubtedly be destroyed. If one has doubts, he can never achieve peace and Bliss in the world, nor in the after-world.