ἐν 
En 
By
τούτῳ 
Touto 
γινώσκω 
Ginosko 
we know
ὅτι 
Hoti 
ἀγαπάω 
Agapao 
we love
τέκνον 
Teknon 
θεός 
theos 
of God
,
ὅταν 
Hotan 
ἀγαπάω 
Agapao 
we love
θεός 
theos 
,
and
τηρέω 
Tereo 

Holman Christian Standard Bible®, Copyright © 1999, 2000, 2002, 2003, 2009 by Holman Bible Publishers.