¹ tn Technically this ὅτι (Joti) clause is subordinate to the verb περιπατῆτε (peripathte) at the end of v. 6, giving the reason why the readers should walk in the commandment to love one another. But BDF §456.1 notes that subordination “is often very loose” in such cases and can be translated “for.” Thus the ὅτι assumes something of an inferential sense, drawing an inference based on what has preceded.

¹ tn It could be argued (1) that the ὅτι (Joti) at the beginning of 3:11 is grammatically subordinate to the preceding statement at the end of 3:10. As BDF §456.1 points out, however, “Subordination with ὅτι and διότι is often very loose…and must be translated ‘for.’” Thus (2) ὅτι assumes an inferential sense, standing at the beginning of a new sentence and drawing an inference based upon all that has preceded. This is confirmed by the structural parallel between the present verse and 1:5.

¹ tn A second causal ὅτι (Joti) clause (after the one at the end of the preceding verse) is somewhat awkward, especially since the reasons offered in each are somewhat different. The content of the second ὅτι clause (the one in question here) goes somewhat beyond the content of the first. The first ὅτι clause, the one at the end of 5:6, stated the reason why the Spirit is the witness: because the Spirit is the truth. The second ὅτι clause, here, states that there are three witnesses, of which the Spirit is one. It is probably best, therefore, to understand this second ὅτι as indicating a somewhat looser connection than the first, not strictly causal but inferential in sense (the English translation “for” captures this inferential sense). See BDF §456.1 for a discussion of this ‘looser’ use of ὅτι.