“Pure and simple” Christianity is like an entrance hall that connects with the various rooms of the house.
However, it is in the rooms of the house, and not in the hall, that the fireplace and the chairs are, and where the meals are served.
The hall is a waiting room, a place from which one can open the various doors, and not a place to live in.
To live in, as I believe, the worst of the rooms (whichever it may be) is preferable.
You must persevere in prayer, begging for the light; and, of course, even while still in the hall, you must begin to try to obey the rules common to the whole house.
Above all, you must continually ask yourself which of the doors is the true one; not which of them has the prettiest paint or the best ornaments.
In plain language, the question to ask should not be: “Do I like these rituals?”, but rather: “Are these doctrines true? Does the sacred dwell here? Could my reluctance to knock on this door be due to pride, or to a personal taste, or to the whim of not sympathizing with its keeper?”
When you arrive at your room, be kind to the people who chose other doors, as well as to those who are still in the hall.
If they are in error, they need your prayers even more; and, if they are your enemies, you, as a Christian, have the duty to pray for them.
This is one of the rules common to the whole house!
Excerpt from the introduction of the book: Mere Christianity