This sermon by Martyn Lloyd Jones deals with how to get out of spiritual depressions that some Christians experience during their walk with the Lord.
Psalms 42:5 Why art thou cast down, O my soul? and why art thou disquieted in me? hope thou in God: for I shall yet praise him for the help of his countenance.
Psalms 42:11 Why art thou cast down, O my soul? and why art thou disquieted within me? hope thou in God: for I shall yet praise him, who is the health of my countenance, and my God.
Lamentations 3:19-26 Remembering mine affliction and my misery, the wormwood and the gall. My soul hath them still in remembrance, and is humbled in me. This I recall to my mind, therefore have I hope. It is of the LORD’S mercies that we are not consumed, because his compassions fail not. They are new every morning: great is thy faithfulness. The LORD is my portion, saith my soul; therefore will I hope in him. The LORD is good unto them that wait for him, to the soul that seeketh him. It is good that a man should both hope and quietly wait for the salvation of the LORD.
1 Peter 5:7 Casting all your care upon him; for he careth for you.