Question: "What does it mean to give a sacrifice of praise (Hebrews 13:15)?"
Answer: Hebrews 13:15 says, "Through Jesus, therefore, let us continually offer to God a sacrifice of praise--the fruit of lips that openly profess his name." The terms "sacrifice" and "praise" might seem to be opposites. We think of sacrifice as offering something at great cost to ourselves. Praise, on the other hand, sounds joyful as it bubbles from a grateful heart. However, in the spiritual realm, sacrifice and praise are intertwined.
Praise does not always cost us something. We praise our dogs for fetching the ball and people for a job well done. Praise is often our response to some action that directly benefits us, and we feel generous because we extend it. We often find it easy to praise God from the same motivation. When He has blessed us, helped us, and protected us, we feel generous toward Him. We can sing, worship, and talk about how good He is because we can see it. That kind of praise, although worthwhile, does not cost us anything. It is not a sacrifice.
Then there are those times when God did not come through the way we thought He would. The medical test comes back positive. The spouse wants a divorce. A child is wayward. The mortgage company calls in the loan. God seems very far away, and praise is the last thing to bubble up from our hearts. We can't see His goodness, and circumstances scream that He has forgotten us.
To praise God in those times requires personal sacrifice. It takes an act of the will to lay our all on the altar before a God we don't understand. When we bring a "sacrifice of praise," we choose to believe that, even though life is not going as we think it should, God is still good and can be trusted (Psalm 135:2; Nahum 1:7). When we choose to praise God in spite of the storms, He is honored, and our faith grows deeper (Malachi 3:13-17; Job 13:15).
The command in Hebrews 13:15 says that this sacrifice is to be offered "continually." Our praise of God is not to be based on our opinion of His job performance. Praise cannot be treated as a "reward" we give God for His obvious blessings. Isaiah 29:13 says, "These people come near to me with their mouth and honor me with their lips, but their hearts are far from me." Real praise continues regardless of circumstances. It flows continually from a worshiping heart in good times and bad (Acts 16:23-25).
The "sacrifice of praise" comes from a humble heart that has been purified by fire. It rises from a spirit that has chosen to honor God in spite of the pain that life is causing. Psalm 51:16-17 expresses this idea best when it says, "You do not delight in sacrifice, or I would bring it; you do not take pleasure in burnt offerings. My sacrifice, O God, is a broken spirit; a broken and contrite heart you, God, will not despise."