In this day and age, in this society? Good is subjective to many things. What is convenient, what gives us immediate pleasure, what is popular, or most accepted, in some cases what goes against traditional values is considered to be good, or more “progressive”, or “open minded”, or “tolerant”.
For some people, especially misguided Christians. Good is what they perceive themselves to be. Anything they aren’t is bad, or evil.
Good, however, is “supposed” to be a characteristic of God’s creations. Everything God made is good. Evil is the absense of good. All things are inherently good and good is instilled in every person, this is also called natural law. This is how we instinctively know good from bad without God’s teaching. But only through the teaching of Christ can one expand upon basic good or bad, wrong or right and live a truly good life.