Since you died with Christ to the basic principles of this world, why, as though you still belong to it, do you submit to its rules: Do not handle! Do not taste! Do not touch!? These are all destined to perish with use, because they are based on human commands and teachings. Such regulations indeed have an appearance of wisdom, with their self-imposed worship, their false humility and their harsh treatment of the body, but they lack any value in restraining sensual indulgence.
Colossians 2:20-23

 I  find this passage so good because it's a reminder that we shouldn't be living by "false, worldly, religious, elementary teachings," as one of my study bible notes puts it. We aren't supposed to "combine faith in Christ with secret knowledge and human regulations concerning such physical and external practices such as circumcision, eating and drinking, and observance of religious festivals." NIV study bible notes, Col. 2:8.

Something that has been put on my mind and heart is that faith--a undying belief and trust-- in Christ is the only thing that saves us, but anything that we do that follows God's laws is an outpouring of our hearts. The outward merely reflects the inward. If we have confidence in who God is and what he has done for us, it will show in how we act and in how we treat others.