Hey! Although many may assume from watching the news that Islam and Christianity have been antagonistic against each other, for most of history this was not true (I am not going to pass much judgment on modern relations, as it is within the 20-years rule, but I do personally believe politics/economics often plays a larger role than religion in disputes.)

Within Islam, Christians (along with Jews and sometimes other religions) are known as ahl al-kitāb, or the People of the Book. This means that Christians are entitled to certain protections in an Islamic state as defined by the ʿaqd al-dhimma, or contract of protection. Someone living in this state is known as a dhimmī, a word you may have heard thrown around before. I'm going to quote below some things that I have written before on the status of the dhimmi is Early Islam:

One key aspect about the early expansion of Islam is that it did not attempt to force its way of life upon other people. Under the Caliph 'Umar, it was envisioned that Islam would be for the Arabs, who would exist as a sort of military caste above the conquered people. This meant that the conquered populations were disturbed as little as possible, and conversions were only on a voluntary basis. This precedent was set with Muhammed allowing the Jews and Christians of Arabia to keep their religion if they paid the Jizya (poll tax). This payment would make a member of the religions of the book - Jews, Christians, and later Zoroastrians - members of the protected class, or dhimmi. These people would be reserved from having to pay the aforementioned Zakat tax (a mandatory charitable donation of 1/40th of a persons income, after certain deductions, that is one of the 5 pillars of Islam) and from military service within the empire. This isn't to say that taxes wouldn't get absurdly high though, as Ira Lapidus notes that taxes on peasants could reach upwards of 50% of the value of the goods. It does, however, mean that the Muslim invaders were not hated. In fact, some Christian tribes had allied themselves with the Muslims against the Sassanians or Byzantines.

Oddly enough, the Religions of the Book flourished in the early days of conquest with Islams coming. Many previously repressed sects were able to abound, and apocalyptic messages were numerous. This changed though as time went on. 'Umar II (r.717-720) forbade Christians to hold powerful government positions. Other successive rulers forbade minority religions to ride horses, bear weapons, or show outward religious symbols in public. Repression came in waves, as one Caliph would crack down (Such as Yazid II destroying churches and animal sculptures) and then others relent. Keep in mind through all of this that from the 7th to the 11th century, upwards of half the world's Christians lived under Islamic rule, yet they were not forced to exile or forced to convert by force (at least in large-scale).

So while it is true that Christians had fewer rights than Muslims (with varying degrees of intensity throughout the last 1400 years) it was not as if all Christians were hated. Indeed, Christians were also often able to take advantage of Islamic institutions and customs. They would be allowed to make and sell wine, something forbidden to Muslims, and could even enforce that right within the court system. Wael Hallaq writes within Sharīʿa: Theory, Practices, Transformations (page 167) that:

... Jews and Christians often prevailed in court not only over Muslim business partners and neighbors but also against no less powerful figures than the provincial governor himself.

The Muslim court thus afforded a sort of public arena for anyone who chose to utilize than space for his or her defense

To sum up, I'd like to pull a few quotes from the paper Dhimmi or not Dhimmi?: Religious Freedom and Early Islam by Mark Graham, which I would recommend you to read to get a more complete view of Christians in Early Islam:

Many of these dhimmis within the early Islamic realm were Nestorian or Monophysite Christians. While none of these writers deny that the Islamic conquest was generally violent, several such writers demonstrate clearly that the early Muslims were decidedly more tolerant than their former Christian Byzantine masters.

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A fellow Nestorian and seventh-century patriarch, Isho’yahb actually presents his Muslim overlords as outright favorable toward Christians, and not merely tolerant. His writings provide one of the most complete accounts of relations between the Muslim rulers and the Christians in his region. In a letter to one of his bishops he records that the Muslims “not only do not fight Christianity, they even commend our religion, show honor to the priests and monasteries and saints of our Lord, and make gifts to the monasteries and churches.”

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One of many relevant facts he [Sebeos] records is that the first governor of Muslim-ruled Jerusalem was himself actually a Jew.

I hope that this shows that, at least within early Islam, relations between Christians, Jews, and Muslims were, while not always perfectly harmonious, not characterized by animosity. Islamic powers managed some remarkably religiously-diverse empires, encompassing millions of people from Spain to India, and managed to keep overarching peace and tolerance for much of its rule. If you have any questions, feel free to ask!

Sources

Ira Lapidus, A History of Islamic Societies

Wael Hallaq, Sharīʿa: Theory, Practice, Transformations

Mark Graham, Dhimmi or not Dhimmi?: Religious Freedom and Early Islam

Edit: Forgot a word