Christians: As Christians why do we emphasize certain sins?

A lot of the time Christians like to emphasize certain sins such as homosexuality, murder, or adultery. Why do we do this when the Bible tells us that God views all sin as equally punishable? Do you believe that a lot of Christians are forgetting the whole purpose of Christianity, which is to love God and to love our neighbors as ourselves whether they're gay, straight, bi, a murderer, whatever. If we gossip, lie, steal or don't honor our parents we are just as "bad" as the people we gossip about.