I would like to propose an idea, that our hearts are both good and evil at the same time. We choose each moment to either follow one or the other. One can follow the good in their heart in loving their spouse, but one can also follow the evil in their heart and commit adultery. You cannot be wholly good or wholly evil in the world we live in. Either good or evil will rule your heart however, and for most people evil does.
In Christian circles it is accepted that the heart contains evil, that we are inherently evil. James says in his epistle that we are tempted to do evil by our own desires (James 1:13-15) and we know our desires come from our heart. You can see the effect of evil in a small child who hits his sister because he wants a toy she is playing with. Sin and evil are extremely prevalent in all areas of life and centered in our human hearts.
Our hearts didn’t originally contain evil. God created us originally as creatures like Him, wholly good. He called us good yet sin happened, causing evil to perpetually enter our lives. Wholly good is how we were created to be; it is how our hearts are supposed to be; it is how our God is. We are God’s image bearers, even with the sin that plaques us, thus we still have His good within our hearts.
Evil is a disease. It entered the wholly good hearts of Adam and Eve, infecting them and affecting every single one of their descendants with the exception of Jesus. Because of that infection evil reigns in our hearts, subduing the original good we were made with. Our ruling desires are evil. There does seem to be good still within our hearts though, even with evil’s control. There has to be some good or we would have no capacity for things like love and kindness. Even those who live a life without Christ in sin are able to have compassion on the starving homeless man on the side of the street. Even those who live a life without Christ in sin have the capacity to love their spouse. There is still good within our hearts even though the majority of it is diseased by sin and controlled by evil.
You have a choice in life to either do good or do evil. Without Christ however, we are more likely to do evil than good. As previously said, evil is a disease that takes over control of the heart and subdues the good God placed within us at the beginning. You have a capacity for good but it is not your first choice. The opposite begins to happen when we accept Christ as our Savior. Through His strength we are able to turn the tables on evil and begin to eradicate it from our hearts. Ultimately our hearts will be wholly good again when Christ returns to make us whole like His Father. Until then we still have both good and evil in our hearts. The difference is that good rules and subdues evil more and more as we become like Christ.
This idea of the heart containing both good and evil is one that I have come up with from observation and my knowledge of the big story of Scripture: creation, fall, and redemption. This is just one way of viewing the world we live in and our human hearts. I may be wrong in my philosophy of the make-up of the heart. Maybe it is simply a result of me always looking for the good in humanity. This is my philosophy of the make up of the heart however, and I hope it makes you think.