One principle that I have always lived by is this:

Be grateful and appreciate what you have

There was a time when I was around 35 years old; I was out of work and moving from one part of Canada to the other.
I had no money.
I could have asked for help from the government but I did not want to do that.
As a result, I slept in my car and did not have anything to eat for four days.
On the fifth day, I received a large amount of money from the company that I had been working for, so my life went back to normal.

It was during that time that I realized that if my life included enough good food to eat and a good place to live, then I should always be grateful and appreciate what I have.

So, being grateful for all the blessings in my life is the most important principle to me.

Good topic Sarah

Sarah, this is a very interesting topic! Thank you for bringing it up. As a believer in Jesus Christ's teachings I follow the Bible's principles. I am not supposed to look at men and lust after them, or hate someone, because that is just as bad in God's eyes as actually killing that person. I fail all the time, but I have the Holy Spirit to help me every day. 

I am not sure of the exact difference between principles and laws. I am not sure how to explain it in words. In the first half of the Bible, (Genesis to Proverbs) God gave laws to the Israelite people. These are the Ten Comandments and also other laws about cleanliness and how to properly purify objects and people. These were outward ways to cleanse yourself. They had to be repeated all the time.

In the second part of the Bible (Matthew to Revelation) when Jesus Christ was born as a baby, he fulfilled the old laws. Because he was fully God and also fully man, He could purify us forever. No more burnt offerings or peace offerings. When He died on the Roman cross, he suffered what we should have suffered. He was the last offering needed for sin. He does not have to keep dying to pay for our sins, like in the Israelite's days.

God has to punish sin, because He is holy and cannot look on sin. But now, instead of us being punished for our sin, we can accept the payment that Jesus paid for us. He offers us purification from our sins, if we are sorry for our sin, and turn our backs on sin. If you put your trust and faith in Jesus Christ He will come and live with you. His Holy Spirit will teach you how to follow Him. When you read the Bible, that is like reading a long letter or blog post from God. It is amazing that God wrote to communicate with us. 

"If we confess our sins, He is faithful and just to forgive us our sins and to cleanse us from all unrighteousness."  1 John 1:9