We Should Not Mistake Worn Nerves, Physical Weakness Or Depression For Unspirituality. Many Times Sleep Is More Needed Than Prayer & Physical Recreation Than Heart Searching. - Dr Lewis Spevy Chafer (founder of Dallas Seminary)

God cannot use someone who is not in good health physically, mentally and spiritually. So we need to feed on His Word, cast all our burdens on Him and take rest by sleeping soundly before we engage in any task for His Glory.
So many children of God are wounded soldiers from the circumstances of life and there are so many who drive themselves crazy, in a frenzy to do some work to prove that they are worthy of the God they are serving. They mistake it for zeal for God when, in fact, they need to go to the Fountain of Life to quench their thirst and wash themselves of the dust and grime of earthly living.
Let us therefore find the comfort of His arms and allow Him to refresh us so we can be revived and be filled with His Spirit to undertake what He has prepared for us to do, and all, of course, for His Glory.