Answer
Asalamu Alaikum Mohamed,
Thank you for contacting About Islam with your question.
Before I go into comparing and contrasting Islam and Christianity, I think it is worth mentioning something about “hate”. There is no verse in the Quran or Prophetic Tradition (hadith) that advocates that Muslims should hate anything or anyone.
There are verses in the Quran that effectively forbid Muslims from choosing Christians and Jews as their closest friends and allies, but this only applies to those who are opposing Islam and fighting the Muslims. Even in such circumstances Muslims are not encouraged to hate their enemies.
Defining Christianity
Defining who is a Christian and who is not, is not really an issue in Islam or a task for Muslims. There are certain excesses that some Christian groups indulge in and these are refuted in the Quran. Some Christians will agree with the assertions of the Quran some will not. For example, we find the following verse on the Trinity:
{They do blaspheme who say: God is one of three in a Trinity: for there is no god except One God. If they desist not from their word (of blasphemy), verily a grievous penalty will befall the blasphemers among them.} (Quran 5:73)
Many Christians would not subscribe to the wording here that “God is one of three”, rather they would say God is one, but is made of three persons, father, son, and holy ghost. I don’t want to go into the convolutions that they make. And I certainly don’t want to justify them.
All I will say is that if I asked many Christians “Is God one of three?”, they would say “No”. Other refutations of the teachings of some Christians can be found in the Quran; but, again, some Christians will claim that those verses don’t apply to their variety of Christianity.
Differences
One key point of disagreement is perhaps best shown in the Quran in the following verse:
{Say: “O People of the Book! come to common terms between us and you: That we worship none but God; that we associate no partners with Him; that we erect not, from among ourselves, Lords and patrons other than God.” If then they turn back, say: “Bear witness that we (at least) are Muslims (bowing to God’s Will).} (Quran 3:64)
In Islam, there is no established church to which we must turn in order to find Allah’s forgiveness and guidance. We can go directly to Allah Almighty for forgiveness and to the sources of the Quran and the historical records of Muhammad’s (peace be upon him-PBUH) living example for guidance.
By setting up an institution with the unique authority to set out morals for people, Christianity opened the door for the corruption of the religion through the corruption of the Church.
To this point, quite early on, obeying the Church for many people meant disobeying the revealed laws of God. To some extent, this has changed in recent times as the Catholic Church has become only one of many churches.
Another verse in the Quran that makes this clear is:
{So, if they dispute with you, say: “I have submitted my whole self to God and so have those who follow me.” And say to the People of the Book and to those who are unlearned: “Do you (also) submit yourselves?” If they do, they are in right guidance, but if they turn back, your duty is to convey the Message; and in God’s sight are (all) His servants.} (Quran 3:20)
But still, there is the prevalent idea that “salvation” is through placing yourself in submission, not primarily to God, but to your church and the doctrines it teaches. This is the real source of shirk (attributing partners to God) in much of Christianity. Trinity is just part and parcel of its attempted justification.
This difference has led to a doctrine of exclusive “salvation” for the Catholic Church and for many other churches and sects.
This is a big problem for Christianity and has led to bitter, often violent conflicts among the adherents of the various churches (incidentally, this is why the U.S. constitution set out to keep the state from supporting any church).
Islam refutes such exclusionary claims of “salvation”, as is clear from several verses in the Quran. One in particular states:
{And they say: “None shall enter Paradise unless he be a Jew or a Christian.” Those are their (vain) desires. Say: “Produce your proof if ye are truthful.” Nay, whoever submits His whole self to God and is a doer of good,- He will get his reward with his Lord; on such shall be no fear, nor shall they grieve.} (Quran 2:111-112)
Similarities
Moving on to the similarities. Both Islam and Christianity accept Jesus as a teacher of God’s guidance. And Muslims and Christians have in common the adherence to those teachings.
This gives a large area of common ground with regards to general morality and shared values. This, of course, depends on the sect of Christianity and the individual Christian, but there are some who are indeed very close to us, as we read in the Quran:
{Strongest among men in enmity to the believers you will find the Jews and Pagans; and nearest among them in love to the believers you will find those who say, “We are Christians”: because among these are men devoted to learning and men who have renounced the world, and they are not arrogant.} (Quran 5:82)
Hope this help answer your question. Please keep in touch.
Walaikum Asalam.
Please continue feeding your curiosity, and find more info in the following links:
Between Islam and Christianity: Did Jesus Die?
Is Islam the Continuation of Christianity?