You don't have to be religious to be spiritual.Being spiritual just involves getting in touch with your inner strength and drawing on that to take you through challenges.
Spend some time with a spiritual leader. This can be someone who shares your faith. Or perhaps talk to a friend or family member whose advice you trust and radiates peace.
Meditate in the privacy of your bedroom or a luxurious, relaxing bath. You can also find peace and contentment meditating outdoors surrounded by the sights, sounds, and smells of nature. Connect with your inner self. From that connection you'll be able to build your confidence and quell any doubts.