There is a concept that has had a stranglehold on the lives of many believers and that is that people are basically evil.
Theologically, there is truth in what is called "Total Depravity." But that has to do with the fact that there is nothing we ourselves can do to merit God's favor. When God created the human race, we, like the rest of creation, were created good. Our first parents' rejection of God's instructions profoundly affected our nature, but did not eradicate the image of God in us. While we cannot claim moral goodness due to our inherited sin nature, there is much of God's goodness still in all people.
Some people say that we don't deserve God's love. While it is true that we deserve the consequences of our wrongs, God loves us, because we are his creatures. He looks upon us with compassion, desiring to bestow mercy on us. He loves us so much that he sent his Son to rescue us. We are truly worth something in his eyes.
Not only do we still possess the image of God, those who have been restored to right relationship with God have been given new hearts in which God himself dwells. In spite of this, many believers still think that their hearts are wicked. While it is true that there is a struggle in our hearts, the true believer has experienced a radical internal change. God is working both in and through us. The presence of God in the believer ensures the good is the greater force.
For a more thorough treatment of this issue, I recommend John Eldredge's "Waking the Dead - the Glory of a Heart Fully Alive."