It was LORD KRISHNA who HIMSELF gave this sermon to Arjun, when Arjun was facing the biggest crisis in his life. The complete sermon is compiled in the “Holy GITA”. However, the gist is as under:

Whatever has happened, there was some good in it.
Whatever is happening now, is happening for the good.
And whatever happens subsequently, will again be for the good (which you may be unable to see now).

Is there any reason for you to worry?
What have you lost for which you cry or feel bereaved?
What did you bring with you to this world that you have lost?

What did you produce, which has been destroyed?
You did not bring anything when you were born.
Whatever you have, you have received from Him,
and whatever you will give, you will give to Him.
You came empty handed and
you will leave this world the same way.
Whatever is yours today was somebody else’s yesterday and will be somebody else’s tomorrow.
Change is the law of this world. Hence cheer up and continue doing your job with all your heart and soul. Do not worry about the end result as HE would be determining it.