A few weeks ago I was on my way to an evening church service on Monday night. I had worked that day and was exhausted. Just to prove the point that I was exhausted, Rebecca drove us there because I was too tired to drive. We had both had long, wearying days, and both were complaining a bit. I was so tired I didn't feel like I could handle her problems as well as my own (i.e. I can complain, but I can't handle you complain - oh dear, you probably can't really handle me complaining so well at the moment either), and so I suggested that we both just keep quiet for a bit. Suddenly I had a thought to sing. Mind you, I didn't exactly feel like singing or praising God, but I thought I would give it a go. I sang one line, "Rejoice in the Lord and again I say rejoice." Suddenly my spirits lifted. I didn't feel so down or worn out. I suddenly felt like the air must have cleared, and started talking as so, and realised that I was the only one who felt the difference.
The others had not had the moment of lifting that I had in my Spirit. They didn't lift Him above, and their feelings did not change. In the moment I lifted God above my feelings, my feelings changed. Yet previously I was the tiredest and grumpiest of the lot!
God says many times in His word to rejoice always, and to give thanks in all things. I would suggest that this is for more reason than "All things work together for good to them that love the Lord and are called according to His purpose." This is because as we praise Him, we are lifted up with Him. He lifts us up above the circumstances that weigh us down. In worship we are "casting our burdens (cares) upon Him".
And lest I make this sound dreary, rejoicing in the Lord is praising Him! It is joyful, and even if you don't feel joyful when you first make the choice to worship Him rejoice, and see how His joy (which is your strength) can make a difference.
"If I be lifted up... I will draw all men unto me."