The life in you is dull. On the day you do pranayam or Sudarshan Kriya, you are so alive. Every cell in your body is alive, and then there is no doubt in the mind. You feel so wonderful because of this. There is no split in your consciousness. Doubt is the split. A portion is awake and another major portion is asleep – the unfulfilled state of consciousness.
When the prana is low, you feel unfulfilled. And when the prana is full, you are so fulfilled. So, when you have doubts, do more sadhana, practice. This is called shraddha, faith, the opposite of doubt. It starts with self-doubt – doubting the self, doubting everything and doubting the Divine.
There are three types of faith: in the divine, in the universe and in the world. Faith in your Self, faith in the world and faith in something we do not know, the Divine. Start from anywhere. Any point will lead to all three. When doubts arise in you, meditate, do pranayam and prayers, and see whether the doubts remain. There is a shift in your consciousness.