When I took Greek in college, 1 John was our primer for learning and translating be language. The other letters of John are similar, in that they are not complicated in their language, but in their thought. That is our word for the day.
Don’t do evil. Do good. The godly do good and not evil. Remember that the next time you are wondering if you can give in to temptation. If you are God’s, then you don’t have time for evil. Yet, we are human, and part of us is always tempted by the world and its desires.
If you’ve given in, don’t despair. God is also gracious. If would be His again, repent, confess your sins, ask for His forgiveness. He is faithful and just to forgive. But don’t go back like a dog to vomit. Repentance means you don’t want to go back. Mean it when you say it.
Hope this helps.