What do you consider to be evil?

Good and evil are simply end points on a spectrum, rude falls on the evil side of the midpoint.

if you are not showing love toward your fellow man then you are evil

That which God defines as evil.

Evil is the opposite of good.

Only God is good, so evil is that which is not of God.

Biblically speaking, all of us are evil. And by evil I mean corrupt. We are corrupt versions of what God originally made. As a Christian I learned that God is going to take care of that corruption, he has already made atonement for it and a promise to cleanse us of the nature of it. We won't be like this forever. My job is to spread his word about that, becoming sinless is an impossible task. It's even more dangerous if I think I actually became sinless by my own effort. So to me, sin is corruption. I have the nature of corruption that causes me to have the ability to do wrong things. 

Bigoted people who strive to hurt others and ruin their lives, because they cannot fathom anyone else living by a "code" that doesn't match their own.  Which is why religious people, Christians especially, are horribly hateful, evil and reprehensible.  What's worse - none of them live by their own code!  They never walk their talk! Just read Christ's NT teachings - you'll see: ZERO Christians live by his NT expectations

There is a difference between being a badass and being a bad person. There are people who believe in good, and there are people who believe in greater good but are called evil. 

Deliberately hurting others usually IS evil.  And deliberate rudeness is usually meant to hurt.

Think about that.

IMHO, it's easy to determine if a person is evil.

Do they go by the Golden Rule (Mt 7:12)?  That is, are they comfortable treating people in ways that they would NOT like if treated that same way?  If so, they are evil.

In your case, my guess is that you don't like it when people are rude to you, but are comfortable being rude to them.