The gratitude the writer asks for in Hebrews 12:28 is to be expressed in the form of reverence and awe (let us be thankful and so worship God with reverence and awe). The “and so” suggests he’s interested in gratitude not just for itself but as a means to the worshipful spirit he wants them to possess. This relationship between thankfulness and worship/praise is expressed frequently in the psalms (Psalm 95:2, 100—esp. v. 4) and it’s why praise is often spoken of as giving thanks (7:17,35:18, etc.).
For the Hebrew writer then, if we’re not reverent, we’re not grateful. To be overly casual with God is not, as some suppose, a mark of great spirituality—it’s indicative of a lack of appreciation for who God is and what He’s done for us. A simple test of reverence is to ask ourselves the question, “Is God living in my world or am I living in His?” The first is the default setting of the world, while the latter is the default setting of the kingdom. This is our Father’s world!
Recognizing it is our Father’s world is an act of bare faith that opens the eyes of our heart to see what is unseen. Humanity is no longer something that was swimming in the sea, started swinging in a tree and now it’s me. We are fearfully and wonderfully made. The universe is not a vast, bleak abyss that is the result of enormous amounts of time and chance, but something that proclaims God’s power and majesty.
We might be tempted to think that the worship the writer speaks of has to do with the kind of activities we do in our church buildings, but this doesn’t appear to be the case. Although the chapter ends here, the discussion doesn’t. The instructions to love one another (13:1), show hospitality to strangers (v. 2) and remember those in prison (v. 3) are all brought up under the umbrella of worshiping God with reverence and awe.
But he doesn’t stop there!
He goes on to speak of honoring our marriage vows (v. 4), keeping ourselves free from the love of money and being content with what we have (v. 5). He goes on to mention other things before adding, And do not forget to good and to share with others, for with such sacrifices God is pleased. Then mention of sacrifices makes it clear that the discussion of worshiping God is still in view.
All of this should open our eyes to a couple of things. Worship is about revering God rather than the acts designed to bring praise to Him. We would do well to recognize the difference. A child’s off-key singing of Jesus Loves the Little Children is more pleasing to our Father than a professional concert experience in an assembly that is more concerned about style than substance.
The other truth is that living with reverence to God is a 24/7 activity. It is not only related to how we treat God, but how we treat others. Understood in this light, it takes worship of God out of the building and into every phase of life. It is what gratitude looks like.