I know the bible tells us that God is absolute good. There is no darkness or negative in God. In God there is no balance of good and evil. It is not easy to think about because nothing in the world is like that. I can not imagine what it was like for Jesus in this world.
Think about the word purity. Define it, we define it by what it is not. Purity is not hate, anger, it is not defiled. The list can go on. (The list of what purity is, is a short one; love, goodness.) Is there balance in something that is pure? What is pure in this world?
Some people do good things, we all have done some bad things. Some days we feel we are just living our lives and that is all we think we are doing. The bible tells us a lot more is happening. Every thought everyone has matters, each one is a big moment of choice for us. Balance is not what the bible tell us we can obtain. With the Holy Spirit we can get back to God created all the world and saw that it was good. Not balanced, just good. That is what the bible tells us we can obtain with God.
The bible says the sinners heart is evil. All that is saying is a sinners heart dosen't have God in it. Without God all that is left is evil. But Jesus said that even an evil person knows how to give good gifts to their children. So the bible says evil people can do good things. But those good things won't last forever. If they are not done with a heart that God desires.
(Edited to add the words "with God" to the end of my 3rd paragraph.)
The point is we do not always know what is good or bad, we have to rely on what God says is good, that's what faith is.