REQUIRED BY GOD

One cannot obtain God's favor through works of righteousness alone. He is not swayed by the bargaining chips you place before Him in a futile attempt to offset the sin in your life. The Lord is only interested in your offerings as they emanate from an established relationship with Him.

He has shown you, O man, what is good; And what does the Lord require of you But to do justly, To love mercy, And to walk humbly with your God?  Micah 6:8

These things cannot be accomplished without the Holy Spirit's work in the life of a born-again believer.

Feinberg: The piety that God approves consists of three elements: strict adherence to that which is equitable in all dealings with our fellowmen; a heart determined to do them good; and diligent care to live in close and intimate fellowship with God. Liberals who love to make a religion out of this verse fail to realize that these requirements of the Law are impossible to fulfill by the unregenerate man. 

No one can do what God requires until they first come to Him as broken sinners in need of a Savior. Unsaved people who think they are 'doing justly, loving mercy, and walking humbly with God' are nothing more than pharisaic actors on a stage (no matter how moral their lives may appear). 

Not by works of righteousness which we have done, but according to His mercy He saved us, through the washing of regeneration and renewing of the Holy Spirit. Titus 3:5

You can’t 'do justly' until you’ve been justified by faith. 

You can't 'love mercy' if you’ve not personally accepted God’s mercy. 

You can't 'walk humbly with God' until you bow before Him, confess your sins, and claim His promise of forgiveness.

Spurgeon - The prophet mentions three things that the Lord required of his people: “To do justly:” here are the equities of life. “To love mercy" here are the kindnesses of life. “And to walk humbly with thy God.” Talk no more of your outward ordinances, your will-worship, with an abundance of music, or human eloquence and learning. These things delight not the Lord; no offering is acceptable unless the outward conduct shows that the heart is right with Him.

Outside of a relationship with Jesus Christ, it is impossible to walk in obedience to God's requirements. But if you truly abide in Him, these traits will naturally surface as evidence of redemption.