John 8:55-58

and ye have not known him: but I know him; and if I should say, I know him not, I shall be like unto you, a liar: but I know him, and keep his word. Your father Abraham rejoiced to see my day; and he saw it, and was glad. The Jews therefore said unto him, Thou art not yet fifty years old, and hast thou seen Abraham? Jesus said unto them, Verily, verily, I say unto you, Before Abraham was born, I am.