If we receive (ε λαμβανομεν). Condition of first class with ε and the present active indicative, assumed as true. The conditions for a legally valid witness are laid down in Deuteronomy 19:15 (cf. Matthew 18:16; John 8:17; John 10:25; 2. Corinthians 13:1).

Greater (μειζων). Comparative of μεγας, because God is always true.

For (οτ). So it applies to this case.

That (οτ). Thus taken in the declarative sense (the fact that) as in John 3:19, though it can be causal (because) or indefinite relative with μεμαρτυρηκεν (what he hath testified, perfect active indicative of μαρτυρεω, as in John 1:32; John 4:44, etc.), a harsh construction here because of μαρτυρια, though some MSS. do read εν to agree with it (cf. verse 1. John 5:10). See οτ εαν in 1. John 3:20 for that idiom. Westcott notes the Trinity in verses 1. John 5:6-9: the Son comes, the Spirit witnesses, the Father has witnessed.