It is obvious that such a statement can easily lead to presumption, however. That is, a person can claim a certainty that is in fact unfounded. Or, to put it in John’s words, he can claim to be a child of God when actually he is not or, worse, when he is a child of the devil. How can a person who claims to be a believer guard against such presumption? In answer to this problem John offers three tests which in one form or another are repeated again and again throughout the letter. They are,