Mendelssohn Psalm 42 First part, ‘Choir’.

Psalm 42:9-11

9 I say to God my Rock,
       “Why have you forgotten me?
       Why must I go about mourning,
       oppressed by the enemy?”

 10 My bones suffer mortal agony
       as my foes taunt me,
       saying to me all day long,
       “Where is your God?”

 11 Why are you downcast, O my soul?
       Why so disturbed within me?
       Put your hope in God,
       for I will yet praise him,
       my Savior and my God.

Verse 9 starts with a declaration of faith, “God My Rock”, but then falls back on the human weakness of feeling sorry for yourself. Why has God forgotten you?  You morn of being oppressed by your enemies.

Verse 10 has more self pitying questions. Why are you suffering the agony of your foes, who torment you by asking “Where is your God?”
Verse 11 supplies the answer.  Put your hope in God.  When you refocus your energy from questions to singing praise to your Savior, your doubts and fears are replaced by the hope you found with salvation.
Why is faith so important?
Without faith those moments of doubt and fear, that fuel self-pity, will overwhelm you.  Despair will take control of your life.
What is the cure for self-pity and despair?
The answer is finding a source of faith that gives you hope for the future.  Then to keep reinforcing this foundation until it is strong enough to withstand any of the agonies you may experience in living, or torments of those who work against you.
2) As an Atheist my faith is grounded in understanding the forces in nature that control the world I live in.
My faith in a better future becomes stronger as I look back over the billions of years of evolution that gave birth to my species, homo sapien.  Natural Selection will insure that as long as I learn to keep asking better questions, as my ancestors did, I will find better answers.  I will make my world a better place to live in, for myself, and future generations.
The first tribes of man danced and sang around a camp fire, in praise to the forces in nature.  I join them in celebration of the miracle of life.