Remember that without faith you can do nothing; therefore ask in faith. Trifle not with these things; do not ask for that which you ought not.
The context of this statement was to Oliver Cowdery when he was seeking the gift to translate ancient records by revelation. This statement is true on many levels. In the Prophet Joseph's Lectures on Faith, we learn:
Faith is ... the principle of action in all intelligent beings. If men were duly to consider themselves, and turn their thoughts and reflections to the operations of their own minds, they would readily discover that it is faith, and faith only, which is the moving cause of all action, in them; that without it, both mind and body would be in a state of inactivity, and all their exertions would cease, both physical and mental.
This is a simple, yet powerful concept. I have never been in a state of complete inactivity, but I can imagine that those who struggle with depression perhaps from another perspective can be seen as "faith-challenged". For those who find it difficult to get up in the morning, I imagine that they have very little hope, which we have read is the predecessor to faith. In this frame of mind, when one cannot see things working out in the long or the short run, it must be very difficult get out of bed and have faith to go about one's day. While I have experienced this type of despair from time to time in my life, it has never been severe and so I can only speak partially from experience.
While all intelligent beings operate by faith, it is important to remember that only faith in Jesus Christ has the power to produce the fruit of salvation.
[H]e cometh unto his own, that salvation might come unto the children of men even through faith on his name; (Mosiah 3:9)
And as Moses lifted up the serpent in the wilderness, even so must the Son of man be lifted up: That whosoever believeth in him should not perish, but have eternal life. For God so loved the world, that he gave his only begotten Son, that whosoever believeth in him should not perish, but have everlasting life. (John 3:14-16)
Jesus saith unto him, I am the way, the truth, and the life: no man cometh unto the Father, but by me. (John 14:6)
I could go on quoting a very long list of scriptures here, because frankly, this has been the theme of the gospel all the way through. Faith in Jesus Christ produces salvation! It also has a thousand other priceless and wonderful side-effects.