What is John Locke's view on religion?

Locke developed what became a common view on religious tolerance. He argued that on a practical level, no man can be certain by means of reason what is true and what is not, so having an established religion was contrary to seeking truth. He also argued that even if rulers were certain for themselves that a certain religion was the truth, subjects might disagree, so they would be less than freely willing to obey the ruler, so having an established religion was bad for government. Thirdly, he noted that where religions competed, having one established religion would almost certainly lead to unrest, so having one single established religion was bad for public peace.

Thus all religions should be tolerated by government, and none endorsed.