Summary: Praise should characterize the life of a believer
1Praise the LORD! Praise, O servants of the LORD; praise the name of the LORD. 2Blessed be the name of the LORD from this time on and forevermore. 3From the rising of the sun to its setting the name of the LORD is to be praised. 4The LORD is high above all nations, and his glory above the heavens. 5Who is like the LORD our God, who is seated on high, 6who looks far down on the heavens and the earth? 7He raises the poor from the dust, and lifts the needy from the ash heap, 8to make them sit with princes, with the princes of his people. 9He gives the barren woman a home, making her the joyous mother of children. Praise the LORD! Psalm 113 (NRSV)
A woman in a worship service was standing with eyes closed, hands raised in prayer and praise. A three year old, standing in the pew in front of her turned around, saw the upraised palms and gave her a high-five!  Worship should be enthusiastic.
On the other hand, have you ever encountered the time when you just plain don’t feel like you have it in you to get up anything approaching worshipful praise? A minister shared that…five or six years ago I visited a church in Connecticut. In the middle of the Eucharistic liturgy, when the whole congregation was kneeling and singing the “Alleluia,” I saw a woman near me with her hands lifted in praise. The thing was, those hands were terribly twisted and gnarled, and she had a pair of crutches near her. Dear Christ, I thought, what makes Christians sing “Alleluia”? Clearly there was something besides self-interest welling up from that woman in the act of praise. 
Another example involves Margaret Sangster Phippen who wrote,
…in the mid 1950s her father, British minister W. E. Sangster, began to notice some uneasiness in his throat and a dragging in his leg. When he went to the doctor, he found that he had an incurable disease that caused progressive muscular atrophy. His muscles would gradually waste away, his voice would fail, his throat would soon become unable to swallow.
Sangster threw himself into his work in British home missions, figuring he could still write and he would have even more time for prayer. “Let me stay in the struggle Lord,” he pleaded. “I don’t mind if I can no longer be a general, but give me just a regiment to lead.” He wrote articles and books, and helped organize prayer cells throughout England. “I’m only in the kindergarten of suffering,” he told people who pitied him.
Gradually Sangster’s legs became useless. His voice went completely. But he could still hold a pen, shakily. On Easter morning, just a few weeks before he died, he wrote a letter to his daughter. In it, he said, “It is terrible to wake up on Easter morning and have no voice to shout, ‘He is risen!’—but it would be still more terrible to have a voice and not want to shout.” 
There is a common thread which runs through stories like these, and, in fact all the human testimony of people who give praise and maintain incredible faith and joy in the worst of circumstances:
7He raises the poor from the dust, and lifts the needy from the ash heap, Psalms 113:7 (NRSV)