Moreover, considering your natural duty, you should not waver as there is no better course of action for a warrior than a battle to uphold righteousness.
Bhagavad Gita - Chapter 2 - Sankhya Yoga - The Yoga of Analysis
O Partha, only the most fortunate warriors are favored with the opportunity to engage in such a war, which has come of its own accord to you as an open door to the higher planets.
But if you decide not to take part in this war of righteousness, your principles of dharma will be lost, fame will abandon you and impiety will be incurred.
For all time to come, people will speak of your infamy, and for one who is great, infamy is worse than death.
Illustrious warriors will believe that you ceased fighting out of fear. You will fall into disgrace in the eyes of those that hold you in great esteem.
Your enemies will insult you with slanderous words, condemning your prowess. Alas, what could be more painful than that?
O son of Kunti, if you are killed you will attain the higher planets, and if you are victorious you will enjoy the Earth. Therefore, be confident of your success – stand up and fight!
Maintain equanimity when faced with happiness and distress, gain and loss, victory and defeat – fight, and in this way you will not incur impiety.
O Arjuna, son of Pritha, I have revealed to you the knowledge of individual consciousness. Now hear how to act upon this knowledge, through which you will be able to release yourself from the bondage of action.
In this activity there is no loss, nor is there any diminution of result. Even the slightest effort performed righteously saves one from the greatest fear.