Sin in 1 John
Commentary on 1 John 1:8
The other way in which John surprises us in this second “if” is by speak¬ing of “sin.” He has not even used the word up to this point. Now, with no further introduction of the matter, John declares that if we live in light not only do we have fellowship with one another, but also “the blood of Jesus his [God’s] Son cleanses us from all sin.” There is no further explanation here as to how the blood of Jesus purifies, but the connotations of the phrase may lead us in two different but parallel directions: on the one hand, it may refer to the long-standing tradition in the Law of Israel of purification by means of ritual sacrifice; on the other, “blood” is the equivalent of life, and therefore it is possible to read these words as referring to the life of Jesus, and not only to his death—in which case John is returning to his earlier theme of the eternal life that has been revealed.
In any case, the theme of sin, introduced for the first time at the end of the first pair of “ifs,” serves as a link to introduce the second pair, which begins with “if we say that we have no sin.” As one compares this second set of “ifs” with the first set, one notes that, while appearing to repeat what the first set said, it actually moves the argument further. On the negative side, the lie is not only to others, in presenting ourselves falsely; it is also in that “we deceive ourselves” (1:8). And not only do we not “do” the truth (1:6); but rather, “the truth is not in us” (1:8). On the positive side, it is not now a matter of what we do or how we walk, but rather of confessing: “if we confess our sins … ” (1:9). In the first pair of “ifs,” we were called to do something, to walk in a certain way. In this second half, we are not told to do anything but confess. And, at the end of this second set of “ifs,” the theme of cleansing from sin appears once again, thus serving as one of those “batons” that various sections of the Epistle seem to hand to the following section so as to provide continuity in the discourse.