One of my favorite passages on worship is Romans 12:1, and I believe that this verse gives us a true definition of what it really means to worship. Let's read this verse from the NIV and the Amplified Bible.
I APPEAL to you therefore, brethren, and beg of you in view of [all] the mercies of God, to make a decisive dedication of your bodies [presenting all your members and faculties] as a living sacrifice, holy (devoted, consecrated) and well pleasing to God, which is your reasonable (rational, intelligent) service and spiritual worship.
(The Amplified Bible)
The first thing that we see in this passage is our motive for worship. "In view of all the mercies of God." When we worship, the first thing we are asked to do is to take into account the mercies of God. We are to have an "attitude of gratitude" toward His mercies. So the question that we need to ask ourselves is, "Do the mercies of God ever cease to exist?" And obviously the answer is NO! Lamentations 3:22-23 states, "The faithful love of the Lord never ends! His mercies never cease. Great is his faithfulness; his mercies begin afresh each morning." So if we are taking into consideration the mercies of the Lord, then we must do so every day. The Lord's mercy is not something that is recycled. It is not like rollover minutes on our wireless phone service. The Lord's mercies are new for us every day, and as a result, our worship should be fresh and new every day. Worship begins with an encounter of God's mercy.
I like the classic "pulpit" definition of mercy and grace. Grace is receiving favor that we don't deserve, while mercy is not receiving punishment that we do deserve. Friends, we are a sinful people. I can tell you that there are punishments that I should have received because of sin, but because of God's mercy I was spared the punishment. When you think of the mercy of God in this way it should cause an overwhelming feeling of gratitude and humility to rise up within you, and that is the birthplace of worship.