If we say that we have no sin, we deceive ourselves, and the truth is not in us.
Some have interpreted the phrase "no sin" to mean no sin nature or no sin principle. [Note: E.g., Smalley, p. 29.] However this seems out of harmony with John’s other uses of "to have sin" (cf. John 15:22; John 15:24; John 19:11). Rather, it probably means to have no guilt for sin. [Note: Robert Law, The Tests of Life: A Study of the First Epistle of St. John, p. 130; Robertson, 6:208.] 