In other words, "What shall I bring to Him? How shall I serve Him? How shall I honor Him? How shall I please Him? How shall I glorify Him?"
That is pretty clear. In these places where statements like this are made, we understand that they encompass very much. They are giant concepts—mercy, justice, and faithfulness. And there is very much within them that needs to be expounded upon. But it gives us a hook upon which to order our life, so that we understand (at least in an overall way) the direction that we are to go.
What we can find in regard to the Colossians is that they were not motivated by truth to do this. They were not motivated by faith in God to do this. Does this mean, then, that sacrifice is of no account? Asceticism is a sacrifice. Keeping the Sabbath is a sacrifice. Tithing is a sacrifice.
We see here in a place like Micah "Wherewith shall I come before the Lord, and bow myself down?" "What should I bring to God?" Then he mentions sacrifice. It can lead the unwary to thinking that God does not want sacrifice. No, no, no. That is not true at all! The day of sacrifice is not over, as Romans 12:1-2 very clearly shows.
We are going to put this together now with the lesson of Colossians. Sacrifice, asceticism, giving things up, giving time up, or whatever it might happen to be—sacrifice without the right motivation, sacrifice without truth, is of no value. It may profit the body for a little while. But in terms of relationship with God, it does not help at all.
So God is not saying, "Do not sacrifice." He is not saying, "Do not discipline yourself." He is saying that to do justly and to love has a higher priority. But all those things have to be done with the right object in mind and seeking the right source of strength. You can tie this right together with Matthew 23:23, that famous verse about tithing. What did Jesus say? He said, "This you should do."
Tithing is not easy. It requires a great deal of discipline and faith. But He said, "This you should do, but do not leave the weightier matters of the law undone—judgment (or justice, or being fair, doing unto others as you would have others do unto you); mercy (kindness, compassion); and faithfulness (loyalty to God). There are some things that are more important than others. And those last three—justice, mercy, and faith—Jesus is indicating are more important than tithing.