You must know that you are in this world with a divine mission.
That all that exists and ever existed depends upon your fulfillment of that mission.
And that if any mountain should stand in your way,
Or any ocean block your path,
Or any quagmire detain you from reaching your goal—
Know that you are on a mission from the Creator of heaven and earth.
And if so, it is absurd that any of His creations should stand in the way of the mission for which He has created you.
It could only be that these are not obstacles. Rather, they are a vital element of your mission, designed to lift you higher, and yet higher.
Iterated and expounded in countless talks and letters. For one stark example, see Likutei Sichot, volume 23, pg. 533
From the Lubavitch Rabbi, the Seventh Chabad Rebbe
By Tzvi Freeman