1 John 2:9(KJV)
He that saith he is in the light, and hateth his brother, is in darkness even until now.
The above scripture tells us that if you are a believer and you hate another believer, you are walking in darkness. This does not mean that you do not agree, it simply means that much as you actually get angry, you are not supposed to hate. By practicing this you are shaped into a much better child of God. So let us all work on our anger and stop hating.
1 John 2:10(KJV)
He that loveth his brother abideth in the light, and there is none occasion of stumbling in him.
In the above scripture, the stumbling being talked about is a believer getting a chance to hurt a brother and he actually does it.