The Church: Locke's Key Ideas

"I say it is a free and voluntary society.
Nobody is born a member of any church; otherwise the religion of parents would descend unto children by the same right of inheritance as their temporal estates, and everyone would hold his faith by the same tenure he does his lands, than which nothing can be imagined more absurd. Thus, therefore, that matter stands. No man by nature is bound unto any particular church or sect, but everyone joins himself voluntarily to that society in which he believes he has found that profession and worship which is truly acceptable to God. The hope of salvation, as it was the only cause of his entrance into that communion, so it can be the only reason of his stay there. For if afterwards he discover anything either erroneous in the doctrine or incongruous in the worship of that society to which he has joined himself, why should it not be as free for him to go out as it was to enter? No member of a religious society can be tied with any other bonds but what proceed from the certain expectation of eternal life. A church, then, is a society of members voluntarily uniting to that end."

- John Locke, excerpt from A Letter Concerning Toleration