This is the translation from the Kingdom Interlinear that the Watchtower promotes on their website
The crucial word is "ean=if ever" I don't see why anyone will translate EAN as "if ever" , it doesn't work. The correct interpretation should be "if(=EAN) you love among yourselves."
(=I'm Greek, with 3 years studies in Koini)
What is the context through the lense of the first few centuries of the church? The type of love Christians portrayed was UNIQUE for the first few centuries and the reason many pagans converted to Christianity, some excerpts below