Principles are general truths. They are fairly universal. They’re good guidelines for say, young parents. E.g., keep ‘em safe, keep ‘em fed, keep ‘em clean and out of the cold. Oh, and teach ‘em to be good. If you do those things, you’ll have a pretty start on the basics.
Some folks would make rules or laws about how best to do each of those things. Then they’ll imply, “If you don’t do it just so, you’re bad.”

Meticulous adherence to law has at least three unhappy outcomes;

1.) when the least detail of the law is omitted, you feel condemnation or judgment, and

2.) one gets so focused on doing every detail of the law, he misses the pleasantness and benefit that keeping the law was intended to give him, and

3.) in keeping to the letter of the law one imagines some form of specialness, or righteousness – an entitlement to recognition. All of this strengthens his attraction to living from performance, which necessarily makes him a stranger to the intimacy of relationship.

God does not wish to subjugate His beloved childrens’ affections or His precious gifts to the cold dictates of principles and rules.