Instead of saying, "I cannot," when one is asked to do something which seems difficult, one should think of God, the unlimited, perfect Mind. Lack of confidence is dispelled as one realizes that man is the expression of this infinite Mind.
Where do lack of confidence and a sense of inability originate? Mrs. Eddy answers this question when she says (Science and Health, p. 223), "Sooner or later we shall learn that the fetters of man's finite capacity are forged by the illusion that he lives in body instead of in Soul, in matter instead of in Spirit."
Perhaps at first one may be dismayed by the thought that he himself has forged the fetters of his finite capacity. But this is changed when he sees that he can put these finite beliefs out of his consciousness through the realization of man's relation to the fetterless Mind.