Everyone and everything has requirements. Our modern devices have power requirements. Our vehicles have fuel and maintenance requirements. Our relationships have requirements. In the verses preceding this, the question is what I can do to make myself acceptable to God; what manner of sacrifice or offering will cover over my sins. What, exactly, does God require from us?
First: justice. All of the definitions of this word; all potential meanings point toward doing what The Law says. Many folks have a problem with this and get their panties in a twist over which laws and how they think they should be given a pass. The short of it is that Jesus summarized the entirety of the OT in two commandments: love the LORD with all your heart, soul, mind, and strength; love your neighbor the way you love yourself … and everyone is your neighbor. The first century church did not saddle non-Jewish converts with any of The Law beyond these obvious commands from Christ and saying that they should not eat food sacrificed to idols; should not eat blood; should stay sexually pure (Acts 15:28-29). What God requires, first and foremost, is obedience.
Second: kindness. This word is slightly richer in meaning, potentially meaning goodness, kindness, or faithfulness. Rather than cherry-pick a meaning that suits me, I will take God to mean all three. He wants kindness; wants me to treat others the way I want them to treat me. He wants faithfulness; wants me to stay true to Him and to be good to my word. He wants goodness; He wants to form His character in me. Who, after all, is good but God (Mark 10:18; Luke 18:19)?
Third: humility. If I am obedient and God’s character is being formed in me, then there will be a temptation toward pride. God wants me to be humble. I heard a definition of humility that I find helpful. Humility is not thinking less of yourself, but thinking of yourself less. That took me a while and I still mentally chew on that. God is not interested in me belittling myself or dismissing truths about how well He is forming His character in me or the great things He has done for me. He wants me to recognize the great things He has done for, in, and through me. He wants me to recognize them as His work. And that is the key. It is His work, not my own. I am not amazing. I am not all that smart or wise. What I am is yet another flawed human being doing his pathetic best while God does far more than I can even imagine I should ask for me and in me and through me. I have seen Him work and I yearn to see it happen again. But I will not; cannot see God working if I am in the way. I am too close to my sad little self to see around me to God. So I need to get me out of the way. Humility starts by fixing my eyes on God. He is the ultimate Other; the most completely Not Me. How can I think of myself when looking on Him?
Those are the requirements: obedience, which leads to Godly character, and humility to guard against the pride that threatens when Godly character is formed. Sacrifice is not required — obedience is. Offerings and tithes are not required (though they are encouraged) — Godly character is. And what does the LORD require of you, but to do justice, to love kindness, and to walk humbly with your God? Nothing else is required.