Overview & Downloads

Monotheism Through the Centuries

This site summarizes several major world religions and provides a visual overview of how the share of the world population following one-God (monotheistic) religions has changed over time. All monotheistic traditions are combined in one trend line so the overall pattern is easy to see.

Download the PDF summary Includes all major religions described on this site, with all one-God religions grouped sequentially (Judaism, Roman Catholicism and other Christian branches, Islam, Sikhism, Bahá’í).

⬇ Download Full PDF Summary

Historical Trend: Share of World Population in Monotheistic Religions

Line chart showing a rough historical trend of the share of world population in monotheistic religions, rising from around 5 percent in year 0 to the mid-50 percent range by 2020. — Estimated combined share of the world population in monotheistic religions. Values before 1900 are illustrative.

Approx. Year	Estimated % of World Population in Monotheistic Religions
0	5%
500	15%
1000	35%
1500	45%
1600	47%
1700	50%
1800	50%
1900	48%
2000	53%
2020	56%

One-God (Monotheistic) Religions Grouped Together

For the purposes of the chart, the following are grouped as monotheistic traditions:

Judaism
Roman Catholicism
Eastern Orthodox Christianity
Protestant Christianity
Anglican / Episcopalian
Islam
Sikhism
Bahá’í Faith
Other smaller monotheistic groups

Notes & Data Sources
• Modern anchor points (1900 & 2000) use published estimates of the global share of Christians and Muslims, especially from large demographic studies and research organizations such as Pew Research Center.
• Recent figures for 2000–2020 assume Christians and Muslims together account for roughly half of the world population, with Jews and other monotheistic communities adding a smaller share.
• Earlier centuries (before 1800) rely on historical reconstructions and are approximate, intended to show long-term trends rather than precise counts.