Sure anyones Christian if they believe in Christ, right? Doesn't mean that they will go to heaven by their beliefs though ;D

Yes they are. Not everyone always follows the rules.

I would hesitate to confuse hate with ignorance. Similar, but still different.

To say would be to judge, that's not for me to do. Alot of people do bad things some of which we have no understanding, since we don't know what's in their hearts we can not know if they are christians or not.

Personally I don't think so but I know alot of people who like to call themselves Christians that I see in the local jails online for shoplifting or drug dealing so being hateful by one who thinks of themselves as a christian really isn't that big of a surprise to me. When I went to church it was told to us 'judge not for he shal be judged' or let he who is without sin be the first to judge. And I'm pretty sure we all sin, not meaning to but we do. I find out everyday I've sinned & didn't even know it was a sin.

Sure, they can be a Christian. I could really go and elaborate the longest-winded answer right now, but I don't think that anyone would understand what I am trying to get at, here. Hypocrisy does not mean you can dismiss any one hypocritical person you see as being a sort of pseudo-Christian. Many Christians are hypocrites. Many people, in general, are hypocrites. It doesn't change what religion they are involved in because of that fact. Religion is different for everyone, as denominations, and even as individuals. This person who is calling someone stupid and arrogant may not see the problem, becuase that person may have done something in their eyes to deserve that. Secondly, an act of hate is, in most simple terms, a sin. If someone is a Christian, then the belief would be that because Jesus died for their sins, and they could ask for forgiveness and mercy, yes? Lastly... Some people really are just stupid and arrogant for a fact. =P [note: before I seem like some conceited jerk, I have to say that I am not preaching to anyone. I just think that is how the Christian religion is believed.]

From what I understand of Christianity, which is not much, humans are not supposed to judge. Judgment is the providence of God. His followers are supposed to pass the word in a kind manner and, if that word is not accepted, not judge the individual. If I am correct in this, judging and hating renders them to be NOT Christian.

There's a difference between being against a person and being against a person's actions.

Yes. No one can purely devote themself to religion. For example, it is wrong to kill animals in Buddhism, yet hardly anyone in China (which is generally a Buddhist country) is a vegetarian or vegan. One of the earliest editions of the Bible stated the Sun revolves around Earth, but now I doubt anyone in this world believes that. I think that as long as someone follows the morals and teachings of a religion they can say that they are religious.

In a way, this is a question about a word: What qualifications must someone possess before "we" will attach the label "Christian" ? Or the question might be: Is "really Christian" the same as "Christian" ? Or the question might be: If I see a self-identified Christian saying hateful words, what should I do?

everyone messes up. thats the defining ideal in christianity: that if you mess up and really mean it when you repent (say sorry to god), he will forgive you.

They're not exactly conflicting ideas.

You can be a Christian and still be imperfect and a sinner. Trying to lead a Christian way of life does not make one ultra holy.

It doesn't qualify a Christian if he fails to identify a stupid or arrogant person, and to do so is not so much an act of hatred as it is applying nomenclature. A stupid or arrogant person is a product of their own volition, and it is not the fault of anyone who declares them as such, but there is the matter of intent and purpose. A Christian, in my opinion, as would any decent person of any faith, seeks to improve a situation or to lead a person to self-help. This requires an attitude of humility and love, and must be without self-promotion and belittling. Regardless, any person who is stupid and arrogant is still a stupid and arrogant person, and it's their own job to fix themselves, if they can. It's not any Christian's fault simply because they pointed it out.

probably just plain ignorant christians as well.

Yes, they can be. When a person becomes a Christian, they do not become perfect. They become a work in progress. Some people take a lot longer to even get to the basics of civility- I am a pastor's wife and I could tell you stories. But I am not going to judge. I simply put it in God's hands and tell Him to deal with it- He often does, in a very short time. I have had a lot of apologies over the years. But, if it is me you are talking about, then I ask your forgiveness. I don't remember calling anyone names, but it is possible. I am a work in progress too.

"Everything we know about God's Word is summed up in a single sentence: Love others as you love yourself.” (Galatians 5:13) "The person who refuses to love doesn't know the first thing about God, because God is love - so you can't know him if you don't love." (1 John 4:8) "If anyone boasts, 'I love God,' and goes right on hating his brother or sister, thinking nothing of it, he is a liar. If he won't love the person he can see, how can he love the God he can't see? The command we have from Christ is blunt: Loving God includes loving people. You've got to love both." (1 John 4:21) "God wants us to grow up, to know the whole truth and tell it in love - like Christ in everything. We take our lead from Christ, who is the source of everything we do." (Ephesians 4:15) “In the same way I loved you, you love one another. This is how everyone will recognize that you are my disciples —when they see the love you have for each other." (Jesus, John 13:34) "Regardless of what else you put on, wear love. It's your basic, all-purpose garment. Never be without it.” (Col 3:14) “Live a lover's life,
 circumspect and exemplary, 
a life Jesus will be proud of: 
bountiful in fruits from the soul, 
 making Jesus Christ 
attractive to all, 
 getting everyone involved
 in the glory and praise of God.” (Philippians 1:10-11) “[Do not let your] freedom [in Christ] be an...opportunity or excuse [for selfishness], but use your freedom to serve one another in love.” (Galatians 5:13, AMP and MSG) "Walk...on the road 
 God called you to travel ...with humility ...steadily, pouring yourselves out for each other in acts of love” (Ephesians 4:2) “Walk (lead a life) worthy of the [divine] calling 
 to which you have been called, [living] with complete lowliness of mind (humility) and meekness (unselfishness, gentleness, mildness), with patience, bearing with one another and making allowances because you love one another.” (Ephesians 4:1-2) “Be agreeable, be sympathetic, be loving, be compassionate, be humble.... No retaliation. No sharp-tongued sarcasm. Instead, bless - that's your job, to bless. ..Say nothing evil or hurtful... ...Make a clean break with all cutting, backbiting, profane talk. Be gentle with one another, sensitive. ...Speak encouraging words to one another. ...Gently encourage the stragglers, and reach out for the exhausted, pulling them to their feet. ...Be mindful to be a blessing” (1 Peter 3:8-10, 1 Thes 5:11-14, Galations 6:10) "Love your enemies. Let them bring out the best in you, not the worst. ...Bless your enemies. ...If you see your enemy hungry, go buy that person lunch, or if he's thirsty, get him a drink. Your generosity will surprise him with goodness.” (Matthew 5:44, Romans 12:14, 20) "Look for the best in each other, and always do your best to bring it out.” (1 Thes 5:11-14) "Above all, love each other deeply, because love covers over a multitude of sins. ...Love covers every wrong. Love makes up for practically anything.” (1 Peter 4:8b, NLT, MSG; Proverbs 10:12) "Be....quick to forgive an offense. Forgive as quickly and completely as the Master forgave you.” (Ephesians 4:32; Col 3:13) "When Jesus arrived, he saw this huge crowd. At the sight of them, his heart broke - like sheep with no shepherd they were." (Mark 6:34) “Love...binds us all together in perfect harmony.” (Col 3:14) "Let us continue to love each other since love comes from God. This is how God showed his love for us: God sent his only Son into the world so we might live through him. This is the kind of love we are talking about —not that we once upon a time loved God, but that he loved us and sent his Son as a sacrifice to clear away our sins and the damage they've done to our relationship with God. ...If God loved us like this, we certainly ought to love each other. . ...We...are going to...love and be loved. First we were loved, now we love. He loved us first.” (1 John 4:7-11, 17-18)