<p>4:21- see on Lk. 10:28.</p><p><em>And this commandment have we from him, that he who loves God, loves his fellow believers also</em>-&nbsp;The &quot;commandment&quot; is to love our brethren as He has loved us on the cross (Jn. 13:34). Here the implications of that are unpacked further. That love of our fellow believers is part and parcel of our love of God, as noted extensively on :20. John keeps on repeating the same things from different angles and slightly playing with the words- in a desperate attempt to get us all to perceive the utterly fundamental importance of love for all our fellow believers.&nbsp; </p>