Salam Dear Mohamed,
Thank you for your question and for contacting Ask About Islam.
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 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 in the Quran to hate their enemies.
Defining who is a Christian and who is not, is not really an issue in Islam. 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 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.
Surah 5 Verse 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. I certainly don’t want to justify them.
All I say here 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 equally some Christians will claim that those verses don’t apply to their variety of Christianity. 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 as 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 ye: “Bear witness that we (at least) are Muslims (bowing to God’s Will).
Surah 3 Verse 64
In Islam there is no established church which we must turn to in order to find Allah’s guidance. We can go direct to the sources of the Quran and the historical records of Muhammad’s living example. 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 the point, quite early on where obeying the Church for many people meant disobeying the revealed laws. To some extent this has changed in recent times as the Catholic (meaning all embracing) Church has become only one of many churches. 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 (giving partners to God) in much of Christianity. Trinity is just part and parcel of its attempted justification.
Another verse in the Quran that makes this clear is:
So if they dispute with thee, 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 ye (also) submit yourselves?” If they do, they are in right guidance, but if they turn back, thy duty is to convey the Message; and in God’s sight are (all) His servants.
Surah 3 Verse 20
This difference has led to a doctrine of exclusive “salvation” for the Catholic church and for many other churches sometimes with apparently tiny differences in doctrine.
This is a big problem for Christianity and led to bitter, often violent conflicts among the adherents of the various churches (Incidentally this is why the USA constitution set out to keep the state from supporting any church). Islam refutes such exclusivist claims as is clear from several verses in the Quran. In particular:
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.
Surah 2 Verses 111-112
Moving on to the similarities. Both Islam and Christianity accept Jesus as a teacher of God’s guidance, to the extent that we know his teachings for sure, 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 Christians concerned but there are some who are indeed very close, as we read in the Quran:
Strongest among men in enmity to the believers wilt thou find the Jews and Pagans; and nearest among them in love to the believers wilt thou find those who say, “We are Christians”: because amongst these are men devoted to learning and men who have renounced the world, and they are not arrogant.
Surah 5 Verse 82
I hope this helps answer your question.
Salam and please keep in touch.