In contrast to sin is the observance of the commandments, which is the fruit and sign of communion with God. To know God, in the biblical sense (cf. Jr 31:34), is not to have an abstract idea of him but to enter into a personal relationship and live in communion with him. For St. John, this knowledge is expressed very concretely; it is equivalent to being with him (3:5) and observing the commandments (3).