What does 1 John 2:3 mean?

One way in which we display evidence of saving faith in Jesus is through obedience. However, as believers, we always have a choice whether to obey or disobey. This particular sense of "knowledge" comes at more than one level. First, is that of salvation. Behavior is a reflection of belief. Actions, however, in and of themselves, are not an infallible test of one's salvation. This is especially true in regards to other people; only God knows exactly what happens in another person's heart (1 Samuel 16:7). However, obedience to the commands of Christ is a primary marker, both for others and ourselves, which at least confirms our place in Christ.

The other, more immediate level of this "knowledge" is in fellowship with God. Even in an existing parent-child relationship, the level of fellowship depends on obedience and communication. A lack of communication does not prove that there is no relationship, but it is certainly not the way things "ought" to be (1 John 2:6). A person who has put trusting faith in Christ is expected to obey (1 John 2:5), but whether or not they do is still up to them.

Critical to understanding this passage is the connection between "knowing" and "keeping" as seen in the Old Testament. The Jewish people were called to show their belief in God through obedience to the Mosaic Law. Even during that time, obedience was the result of faith, not the object of faith. Hebrews chapter 11 offers clear evidence of those godly people throughout the Old Testament who lived by faith, obeyed the Lord, and were recognized for it. Faith was, and is, essential to knowing the Lord.

Here, John places the condition at the end of the sentence. He emphasized knowing Christ as exemplified by obedience. This is in contrasts to verses 5–10, where the conditions will come first.