Life does not get better by chance. It gets better by change.
Doubt entails self-examination because a check on the plausible beliefs and attitudes checks all that constitutes the self. So self-examination entails self-awareness and revising your fake assumptions, a matter of degree. We hold onto the beliefs that maintain a particular conception of ourselves and our relationship to the world. Usually, we have a personal investment in these beliefs; hence these are the ones most resistant to change. This is another reason why changing thinking and actions are so complicated.
Perhaps, to be more objectively analytical, considering action and time are life’s most essential concepts, we should concentrate our beliefs and faiths in taking advantage of what we have and do it in a timely fashion.
All we see and touch is all we will ever have in this life. Your existence is not a dress rehearsal, immerse and absorb it up and do it now.