Are Christians also kafir according to the Holy Quran?

 The Arabic word 'kafir' means infidel to God/disbeliever. God in Arabic pronounce as 'Allah', the only God. Any God can be called Allah as long as it is singularly (meaning one god/monotheism) but the definition of kafir clearly include anyone not belief in Islam and those Muslim that not act according to Islamism.

Although both Christian and Islam are said to be within Abraham tradition along with Judaism but they might pray the different God. There's great degree of plagerism from Islam to Christianity and Judaism. However, the fundamental differents between Islam and Christian are that Christian belief Trinity (one substance, 3 person) but Islam is one substance, 1 person). Jesus die for man's sin and that he is son of God is denied by Islam.

Christian can not be infidel to Islam because there's no privity for fidelity since Allah is clearly not the God Christian belief in.

Christian belief Jesus is son of God, not merely a messenger. It is Islam that infidel to Christian since Christian predate Islam by over four hundreds year and Islam is a fabrication with plagerism from Christian.

Kafir is used to intimidate Muslim who wanted to:

• leave Islam,
• those who refuse the insane command of jihad in the Quran
• Non-muslim that refuse to convert to Islam.
• Muslim who simply perform what his community deem unfit as Muslim.

This is tactic to use psychological and peer pressure to keep Muslim submit and pressure non-muslim to accept Islam (the leader of Islam).

It is a psychological game in which those who obey will be rewarded with paradise in after life and those kafir(rejector/disbeliever, infidel) will go to hell.

Nobody know whether Allah really exist or indeed he speak through angel Gabriel to Mohammed but everyone know Mohammed successfully hypnotised his followers to rage war and killing millions (270millions) of human life, since the inception of Islam. Hard earn money and wealth of others were looted, women were being enslaved as sex slaves and working maids. Non-believers are force to pay jizya. Clearly this is direct contradict to what Jesus have done:

• Jesus face his enemy despite knowing he will be killed (the last supper) vs Mohammed cowardly escape into cave.
• Jesus provide food to the poor vs Mohammed robbed Meccan caravan for food and rage war.
• Jesus never kill anyone and he forgive people vs Mohammed kill people who don't submit him.

None other religion other than Islam keep sex slave or any slavery at all. No religion ask their believer to commit violence and even kill others except Islam.

A rational mind would see it is Islam that infidel and severely distorted Christianity and basic humanity. However, it is indeed a very power ideology to manipulate and control others for their own benefits.