There are several other sayings which seem to belong to the Sermon on the Mount; thus in c. vi, ’If we pray the Lord to forgive us we also ought to forgive’ (cf. Matt. vi. 14 sq.); in c. viii, ’And if we suffer for His name let us glorify Him’ (cf. Matt. v. 11 sq.); in c. xii, ’Pray for them that persecute you and hate you, and for the enemies of the cross; that your fruit may be manifest in all things, that ye may be therein perfect’ (cf. Matt. v. 44, 48). All these passages give the sense, but only the sense, of the first (and partly also of the third) Gospel. There is however one quotation which coincides verbally with two of the Synoptics [Praying the all-seeing God not to lead us into temptation, as the Lord said], The spirit indeed is willing but the flesh is weak ([Greek: to men pneuma prothumon, hae de sarx asthenaes], Matt., Mark, Polycarp; with the introductory clause compare, not Matt. vi. 13, but xxvi. 41). In the cases where the sense alone is given there is no reason to think that the writer intends to give more. At the same time it will be observed that all the quotations refer either to the double or triple synopsis where we have already proof of the existence of the saying in question in more than a single form, and not to those portions that are peculiar to the individual Evangelists. The author of ‘Supernatural Religion’ is therefore not without reason when he says that they may be derived from other collections than our actual Gospels. The possibility cannot be excluded. It ought however to be borne in mind that if such collections did exist, and if Polycarp’s allusions or quotations are to be referred to them, they are to the same extent evidence that these hypothetical collections did not materially differ from our present Gospels, but rather bore to them very much the same relation that they bear to each other. And I do not know that we can better sum up the case in regard to the Apostolic Fathers than thus; we have two alternatives to choose between, either they made use of our present Gospels, or else of writings so closely resembling our Gospels and so nearly akin to them that their existence only proves the essential unity and homogeneity of the evangelical tradition.
Hitherto the extant remains of Christian literature have been scanty and the stream of evangelical quotation has been equally so, but as we approach the middle of the second century it becomes much more abundant. We have copious quotations from a Gospel used about the year 140 by Marcion; the Clementine Homilies, the date of which however is more uncertain, also contain numerous quotations; and there are still more in the undoubted works of Justin Martyr. When I speak of quotations, I do not wish to beg the question by implying that they are necessarily taken from our present Gospels, I merely mean quotations from an evangelical document of some sort. This reservation has to be made especially in regard to Justin.