Martyn Lloyd-Jones in Spiritual Depression:
Do you want to know supreme joy, do you want to experience a happiness that eludes description? There is only one thing to do, really seek Him, seek Him Himself, turn to the Lord Jesus Christ Himself.
If you find that your feelings are depressed do not sit down and commiserate with yourself, do not try to work something up but go directly to Him and seek His face, as the little child who is miserable and unhappy because somebody else has taken or broken his toy, runs to its father or its mother. So if you and I find ourselves afflicted by this condition, there is only one thing to do, it is to go to Him.
If you seek the Lord Jesus Christ and find him there is no need to worry about your happiness and your joy. He is our joy and our happiness, even as He is our peace. He is life, He is everything. So avoid the incitements and the temptations of Satan to give feelings this great prominence at the centre. Put at the centre the only One who has a right to be there, the Lord of Glory, Who so loved you that He went to the Cross and bore the punishment and the shame of your sins and died for you.