So what do we learn from the Bible, specifically the New Testament, about hate (read: extreme enmity, strong aversion, distaste)?
Paul tells us in Titus 3:3 that hating others is characteristic of the lost, not believers. It is an action and attitude that marks our old life before Christ, but not our life in Christ today.
In the book of 1 John, the apostle gives us a number of tests which will prove or disprove whether we are truly God's children. Several of these proofs deal specifically with hate. We learn that anyone who claims to walk in the light but hates his brother, in reality walks in the dark. Everyone who hates is a murderer and does not have eternal life. A person that says they love God but hates their brother is a liar.
These passages make it perfectly clear that haters (using the standard definition) are not children of God. There are, however, some things that the children of God do hate. Jude tells us in his letter to have mercy with fear on sinners, but that in doing so we will find the pollution of the flesh that characterizes their lives very distasteful. In the book of Revelation, Jesus commends the church in Ephesus because they hate--they have an aversion and a distaste for--the sinful deeds of the Nicolaitans. Paul himself, in the book of Romans, grieves over his tendency to commit sin--the very thing he hated. He felt extreme enmity toward his own sinful nature.
If we stop here, it's very simple to understand hate from a Biblical perspective. We can't hate people and claim to be filled with light and truth. We can't be filled with light and truth without finding sin distasteful. But Jesus' teachings introduce some other aspects of hate that many people find difficult to swallow. As I think over this redefinition of hate, I believe that those difficult passages help explain, at least in part, why Christians are sometimes labeled as haters.