हतो वा प्राप्स्यसि स्वर्गं जित्वा वा भोक्ष्यसे महीम्।

तस्मादुत्तिष्ठ कौन्तेय युद्धाय कृतनिश्चयः।।

Meaning -O sun of Kunti , if you win this war you will attain the earthly kingdom and if you loose the war you will attain heaven with respect. So , stand up and fight.

This line from Bhagwad Geeta has always motivated me .It tells us why should we not fear the outcome of our action

It tells us that if you have started something you will either win or loose . If you win it's good , you get or achieve particular thing.

But if we loose , we and the people will be proud of our self.
You will not regret it that you haven't done the thing.

God is with you and the outcome will help you in one way or other way if your intention for it is good.

The ultimate lesson is :

You have started it ,that's the only thing that matter. Do it believing that it is your duty to do it and i is the only thing you can do .