If you believe you can, you probably can. If you believe you won’t, you most assuredly won’t. (Denis Waitley, motivational speaker)
Self-confidence is a characteristic of most successful people. Folks who are unsure of their abilities rarely step “out of the box” to try something new even if they are sure of the soundness of their intentions. Perhaps self-assurance is the result of confidence, not only in your product or idea, but in the One who created and gifted you to be the person you are.
Blessed is the one who trusts in the LORD, whose confidence is in him (Jeremiah 17:7).