In Jesus' day, Israel was looking forward to the coming of their messiah. They expected God to send this anointed one to lead a liberation that would restore their political sovereignty and give them back full control of their land.
Woe to you, scribes and Pharisees, hypocrites! For you tithe mint and dill and cumin, and have neglected the weightier matters of the law: justice and mercy and faithfulness. These you ought to have done, without neglecting the others.
They asked about works (plural), but Jesus gave them just one thing to do: to believe in him. Everything else flows from faith in Jesus. When that's missing we're just running against a wall.
Receiving Jesus in faith means receiving his yoke (Matthew 11:28-30), and that means identifying with him- his heart and his will. However this yoke is not burdensome like the yoke of a self-attempted righteousness, but light.
While the Pharisees only respected appearances, this new law of love works from the inside out. Through faith, Jesus writes a new law on our hearts which compels us into his new way of life.
It's easy to look down on the Pharisees for their blind-spots, but also easy for us to miss the point and become like them in our own way. Everything flows from true relationship with Jesus, and nothing makes sense without him, no matter how great we manage to look on the outside.
May we know Jesus, full of grace and truth, the founder and perfecter of our faith.
I think it would be good to give the name of the author, unless there is a principle involved that I've missed.