A.T. Robertson Commentary 1 John 4:14

"And we have beheld and bear witness that the Father hath sent the Son [to be] the Saviour of the world." — 1 John 4:14 (ASV)

We have beheld (τεθεαμεθα). Perfect middle of θεαομα as in verse 12, though the aorist in 1:1; John 1:14 (εθεασαμεθα). John is qualified to bear witness (μαρτυρουμεν as in 1:2) as Jesus had charged the disciples to do (Acts 1:8).

Hath sent (απεσταλκεν). As in verse 9, though απεστειλεν in verse 10.

To be the Saviour of the world (σωτηρα του κοσμου). Predicate accusative of σωτηρ (Saviour), like ιλασμον in verse 10. This very phrase occurs elsewhere only in Joh 4:42 as the confession of the Samaritans, but the idea is in Joh 3:17.