"Ver. 20: ὁτι εαν καταγινωσκη ἡμων ἡ καρδια, ὁτι μειζων εστιν ὁ Θεος. The difficulty is in the second ὁτι, which is ignored by the Vulgate and A. V. The Revisers (after Hoogeveen, De Partic. p. 589, ed. Schütz. and others) point ὁ,τι εαν in the first clause, which they join with the preceding verse: 'and shall assure our heart before him, whereinsoever our heart condemn us; because God' etc. But this is quite inadmissible, since nothing can be plainer than that εαν καταγινωσκη (ver. 20) and εαν μη καταγινωσκη (ver. 21) are both in protasi, and in strict correlation with each other. Dean Alford suggests an ellipsis of the verb substantive before the second ὁτι, and would translate: 'Because if our heart condemn us, (it is) because God' etc. He instances such cases as ει τις εν Χριστω, (he is) καινη κτισις, which are quite dissimilar; but the following from St. Chrysostom (T. X. p. 122 B) fully bears out this construction; Ὁ ζυγος μου χρηστος κ.τ.ἑ. ει δε ουκ αισθανη της κουφοτητος, ὉΤΙ προθυμιαν ερρωμενην ουκ εχεις; where I have expunged δηλον before ὁτι on the authority of three out of four MSS. collated for these Homilies, the fourth, with the old Latin version, for ὁτι προθυμιαν reading μη θαυμασης, προθυμιαν γαρ. In my note on that place I have pointed out that the ellipsis is not of δηλον, but of το αιτιον, causa est, quia. So in the present instance we might translate: 'For if our heart condemn us, (the reason is) because God is greater,' etc., were it not for the difficulty of explaining how the fact of God's being greater than our heart can be a valid reason for our heart condemning us. I would, therefore, take the second ὁτι for quod, not quia, and suppose an ellipsis of δηλον, as in 1 Tim. vi. 7, where see note."—Otium Norvicense, by Frederic Field, M.A., LL.D. (pp. 153, 15).
Dr. Field s rendering then is: "For if our heart condemn us, (it is evident) that God is greater than our heart."
(2) For the meaning of these verses. All interpretations appear to fall into two classes; as St. John is supposed to aim at (a) soothing conscience, or (b) awakening it. But may he not really intend to leave people to think over a something which he has purposely omitted, and to apply it as required? The saying "God is greater than our hearts, and knoweth all things," probably cuts two ways. If my heart condemn me justly, and with truth, much more so does God who is greater than my heart. But, if my conscience is tenderly sensitive, scrupulous because full of love, God's knowledge of my heart tells in this case on the brighter side, as truly as in the other case it told on the darker side. We may lull our heart. "A tranquil God tranquillises all things, and to see His peacefulness is to be at peace." (St. Bernard in Cant.)