When it comes down to it, the Gospel of John is a book written by Christians and for Christians. But that doesn't mean people of other faiths don't have something to say about it. If Jon Hamm can give his two cents on Kim Kardashian, non-Christians can talk about the gospels.
And whether someone's believing in it or criticizing it, the fourth gospel definitely gets around.
We're just going to come right out and say it: the Gospel of John has some not-so-nice things to say about "the Jews." Why in quotes? Because, the authors basically lump together all the bad guys and non-believers and call them just that— "the Jews."
See, at the time, Christianity was becoming more distinct from Judaism, and lots of Gentiles were converting. These people would have been one of the target audiences for John's gospel; since they probably had no clue what the difference was between a Pharisee and a Sadducee, John's gospel doesn't worry about explaining. It just lumps everyone in together and calls them "the Jews." Oops.
So why the nasty anti-Jewish overtones? Well, around the time John's Gospel was written, some of the Jewish followers of Jesus were being shunned by the Jewish community. We get hints of this when the gospel authors write about Jews who are afraid of being thrown out of the synagogue for liking Jesus (9:22, 12:42, 16:2). The authors weren't exactly feeling the love from other Jews and this translates into their story.
Some people have used these words as justification for hostility or violence against all Jewish people. But "some people" need to get with the program, though, because John's Gospel is not meant to be read as anti-Jewish.
Remember this: you believe that John's Gospel is actually anti-Jewish, you're forgetting one tiny little fact: Jesus and his followers were Jewish. That's right. Throughout the Gospel, you'll see Jesus talking to Jews, teaching in the Jewish temple, quoting Jewish scripture and laws, and celebrating Jewish holidays.
Yeah, Jesus was a real mensch.
Most Christians probably don't know how much Muslims dig Jesus. In true name-dropping form, the Qur'an mentions him about 25 times, as 'Iesa, a prophet and messenger. Muslims claim that the gospels actually lay the groundwork for Muhammad to introduce Islam to the world (3:3) and that all Muslims must believe in what Jesus has revealed (3:84).
But there is that whole crucifixion discrepancy. What's the difference? Well, Muslims don't think Jesus was ever crucified. Here's how it goes down in the Qur'an:
[The enemies of Jesus would boast,] "Indeed, we have killed the Messiah, Jesus, the son of Mary, the messenger of Allah." And they did not kill him, nor did they crucify him; but [another] was made to resemble him to them.[…] And they did not kill him, for certain. Rather, Allah raised him to Himself. (4:157-58)
Basically, Muslims think Jesus is far too cool to have been executed. Instead, Islamic tradition teaches that Allah just made it look like Jesus died on the cross, even though he actually ascended into heaven unharmed. The whole crucifixion story means that someone faithful would be allowed to suffer and die, and Muslims don't think God would let that fly.
One other thing. You know the Father, Son, and Holy Spirit situation that the Gospel of John goes on about? Muslims don't agree with that tenet of Christian faith either. They tend to be pretty firm about there being only one God:
Do not say, "Three," desist—It is better for you. Indeed, Allah is but one God. Exalted is He above having a son. (4:171).
Translation: it's a no-go for the Trinity.
Think that Christians have the Gospel of John all figured out? Think again.
There are tons of doctrinal differences to be parsed out in the Gospel of John, but the biggie is Communion.
Christians have been fighting over this one since before The Last Supper—if you follow the Gospel of John's timeline, at least. Remember the passage back in Chapter 6 where Jesus explains that people need to eat his flesh and drink his blood (in the form of bread and wine) in order to be saved? He manages to annoy the religious authorities with this teaching and even loses some disciples. So what does it all mean?
For Catholics, it points to support for—big theological word alert—transubstantiation. Transubstantiation (we'll wait while you attempt to sound it out) is a super complicated idea that very smart people have been thinking about for thousands of years. And we will now attempt to sum it up in one sentence.
Catholics believe that the bread and wine consumed during Communion really become Jesus's body and blood.
The Catechism of the Catholic Church also sums it up nicely: "By the consecration of the bread and wine there takes place a change of the whole substance of the bread into the substance of the body of Christ our Lord and of the whole substance of the wine into the substance of his blood." Because of this pretty heavy significance, only baptized Catholics are invited to partake in the Communion meal.
Many Protestant denominations aren't down with that view. They believe that the bread and wine are a shared meal which symbolize Christ's sacrifice, but don't actually become his body and blood. The United Methodist Church, for one, takes this stand:
Transubstantiation, or the change of the substance of bread and wine in the Supper of our Lord, cannot be proved by Holy Writ, but is repugnant to the plain words of Scripture, overthrows the nature of a sacrament, and has given occasion to many superstitions.
Since the bread and wine don't have any special qualities, some Protestant denominations invite non-Christians to share in the Communion meal, too.