This post contains maps I have made of the distribution of Christians around the world. The maps are based on data from the Pew Research Center and other sources.

Number of Christians by country
Number of Christians by country
Number of Catholics by country
Number of Catholics by country
Percentage of total population who are Christian by country
Percentage of total population who are Christian by country
Number of Protestants by country
Number of Protestants by country

The countries with the highest number of Protestants are the United States, Nigeria, China, and Brazil. The United Kingdom, South Africa, and Germany also have large Protestant populations.

Percentage of total population who are Protestant by country
Percentage of total population who are Protestant by country

Countries with the highest percentage of Protestants are in Northern Europe and southern Africa. The United States, Canada, and the United Kingdom also have a high percentage of Protestants.

Number of Lutherans by country
Number of Lutherans by country

The countries with the highest number of Lutherans are Germany and the larger Nordic countries like Sweden and Finland. The United States also has a large number of Lutherans, particularly in the Midwest. Other large populations exist in Ethiopa, Tanzania, Nigeria, and Indonesia.

Population:
8–10.9 mil.
5–7.9 mil.
3–4.9 mil.
1–2.9 mil.
500–999 thou.
100–499 thou.
50-99 thou.
10-49 thou.
Percentage of total population who are Lutheran by country
Percentage of total population who are Lutheran by country

The countries with the highest percentage of Lutherans are in Northern Europe, particularly the Nordic countries. Greenland has the highest percentage of Lutherans in the world at 98%. A few countries in Africa have a high percentage of Lutherans, particularly Namibia, Tanzania, and Madagascar.

Percent:
<1
1-4
5-9
10-19
20-29
30-49
50-79
80-95
>95
Number of Lutherans by country per 2013 Lutheran World Federation figures.
Number of Lutherans by country per 2013 Lutheran World Federation figures.
Percentage of total population who are Eastern Orthodox by country
Percentage of total population who are Eastern Orthodox by country
Percentage of total population who are Oriential Orthodox by country
Percentage of total population who are Oriential Orthodox by country
Percentage of total population who are other Christian (not Catholic, Protestant, or Orthodox) by country
Percentage of total population who are other Christian (not Catholic, Protestant, or Orthodox) by country