According to Pew Research, if current trends continue then by 2050 there will be nine billion people living on the planet. Approximately three billion will be Christians, three billion will be Muslims, and three billion others will represent various beliefs (both religious and secular).¹

Since Christianity and Islam are the two largest (comprising about 55% of the world’s population²) religions in the world people often wonder where they disagree and how significant the differences are. A brief look at six doctrinal contrasts will help address this question.

First, it is important to note that Islam shares common ground with historic Christianity. For example, both religions are:

• theistic in philosophical orientation
• monotheistic in doctrinal belief
• Middle Eastern in origin
• biblically oriented Abrahamic faiths (they connect to the Hebrew Bible or Old Testament)

However, the differences between the two religions are profound. Since Islam emerged about six centuries after Christianity, we’ll outline how Islam reacts to essential Christian truth claims. As you’ll see, traditional Islam denies the essence of historic Christianity.

Six Systematic Doctrinal Denials

1. Islam denies the Trinity (i.e., tri-unity: One God in three persons). Muslims instead affirm a form of unitarianism where Allah is a single, solitary being (tawhid) with no partners, equals, rivals, or companions. Allah is not begotten nor does he beget; therefore, he has no son.
2. Islam denies the incarnation (i.e., Jesus Christ was God in human flesh: a single person with both a divine and human nature). In contrast, Muslims assert that Jesus was a mere human being. Yet Islam does concur that Jesus was virgin-born, performed miracles, and lived a sinless life.
3. Islam denies the crucifixion (i.e., Jesus’s atoning death on the cross). Muslims instead declare that Jesus either didn’t actually die on the cross (though he may have been impaled) or that someone else took Jesus’s place on the cross. But either way, Islam is not a redemptive religion.
4. Islam denies the imago Dei (i.e., human beings bear God’s image). In contrast, Muslims affirm that such an image would put creatures too close to Allah (the heresy known as “shirk”). Thus in Islamic theology, human beings are not made in Allah’s image.
5. Islam denies original sin (i.e., that human beings are born with a sinful nature and a natural propensity to sin). Instead, Muslims assert that people are born morally good. So Islam rejects the Christian doctrine of the fall.
6. Islam denies salvation by grace (i.e., that human beings are reconciled to God by God’s unmerited favor apart from works). In contrast, Muslims proclaim that personal submission is required to earn paradise. So both paradise (reward) and divine wrath (punishment) are earned.

Both Can’t Be True

While we live in a time that prizes religious pluralism, nevertheless the laws of logic are stubborn things. Given these six systematic doctrinal denials it follows logically that if Islam is true, then Christianity is patently false and vice versa, for Islam denies the very essence of Christian doctrinal truth claims.

Reflections: Your Turn

Why do you think Islam and Christianity are such popular religions? Visit Reflections on WordPress to comment with your response.

Resources

• For a further comparison of Islam and Christianity, see my two books God among Sages: Why Jesus Is Not Just Another Religious Leader (Grand Rapids, MI: Baker, 2017), 159–88; and A World of Difference: Putting Christian Truth-Claims to the Worldview (Grand Rapids, MI: Baker, 2007), chapter 15, 247–63.
• For an introduction to Islam by a Muslim scholar, see Islam: Religion, History, and Civilization by Seyyed Hossein Nasr (San Francisco: HarperSanFrancisco, 2003).