That depends, what colonies you are thinking about.If you are thinking about the United States, that would be Christianity.
The most common religion in the New England colonies were christianity.
christan
Most former british colonies are still Christian. Much hasn't changed in most of the colonies that were under Britain rule.
The Catholic Religion is the most common religion in Peru.
One element all the 13 colonies had in common was the ability to practice their religion freely.
Most were Jerichoholics;)
The most common religion in Libya is Islam.
what is the most common religion in south america
Roman Catholicism is the most common religion in Brazil.
Christianity is the second most common religion in Africa, with Islam being the most common.
The most common religious group in the colonies was the Presbyterian group, which was the religion of some famous founding fathers such as George Washington etc...
The Southern Colonies.