We all know that God is love. Or at least, we ought to. Unfortunately, we don't always know what that means. "God is love, so He won't mind if I..." Honestly though? Yes, He probably will. If there's anything you're doing that you have to justify with "God loves me...", it's likely sin. Otherwise, why are you even thinking "God loves me" in an attempt to justify it?
The truth is, love and hate are equal and opposite forces. If you love something, or someone, you hate that which is opposed to it. You can even hate that which you love if it threatens something else you love. Jesus commands us to love our neighbour as we love ourselves. So, let's imagine that very neighbour breaks into my house and starts threatening my family. Should I say "I love my neighbour, so I'll let them do this"? No, because that's not loving my family, is it?
God being love, therefore, does not mean He loves evil. The very concept of Hell proves that God hates something. The crucifixion proves just how much He hates it. God hates sin so much that even if you repented of it, the only way He could forgive it is if Christ takes the punishment you deserve for it. Everything from the smallest white lie to the most brutal mass murder, God hates. It is contrary to His loving nature. When it comes to sin, hatred is love. So, if God is love, He must have some very powerful hatred in Him as well. If you love Him, you must hate those things too.