1 John 4:16

And we have known and believed
Or have a full assurance and knowledge of, and faith in,

the love that God hath to us;
shown as in many instances, so more especially in sending his Son to be the propitiation for our sins, to be the Saviour of us, and that we might live through him.

God is love; (See Gill on 1 John 4:8):

and he that dwelleth in love;
who dwells by faith upon the love of God as displayed in Christ, and abides in the exercise of love to God and to the saints:

dwelleth in God, and God in him; (See Gill on 1 John 4:13); the last clause, "and God in him", is left out in the Syriac version.