The second major self-designation that Paul Trebilco explores at length is the term ‘believer’ (whether in a noun or a verbal [‘the one believing’] form). This terminology occurs some 79 times in the NT with 65 of them being the substantive verbal form, the rest adjectival form. There is no debate that this same sort of terminology can be found in Josephus, Philo, and 15 times in the LXX we find the substantive use of the verb pisteuo, but what is notable is how much more frequent this language is in the NT. For example, in Paul we have some 150 or so example of the use of the verb or adjective or noun to refer to ‘believers’ and there is a stress frequently on the content of what they believe.
While it is something of an overstatement to say that early Judaism was far more concerned with orthopraxy than orthodoxy, there is some truth in this. There seems to be a much stronger emphasis on orthodoxy, on right theological believing, in early Christianity. Trebilco points out (p. 74) that there is a stress on the present continual tense form of the verb because continued is seen as a necessary condition of (ongoing and final) salvation. Thus the present participle should be rendered ‘the believing ones’.
The singular form of the participle, which emphasizes individual believing is required can be found at places like Rom. 1.16. 10.4, 10.11, but the plural participle is more frequent (see Rom. 3.22;4.11; 1 Thess. 1.7; 2 Thess. 1.10; 2.12). It is important to note that when Paul uses pistis or pisteuo he rarely specifies the object of belief and this is of direct relevance to the debate about pistis Christou in Rom. 3.22,26; Gal. 2.16 (twice), 2.20,3.22; and Phil. 3.9. The literal rendering is of course ‘faith/faithfulness of Christ’ but the traditional translation has been faith in Christ. However, this goes against the fact that Paul rarely specifies an object of faith when using pistis, and furthermore in various of these texts ‘faith in Christ’ is rendered clearly with the use of the preposition ‘en’, which is not a part of this phrase. In my view R. Hays and others are likely right that ‘pistis Christou’ and it’s variants likely refer in a shorthand way to Christ’s own faith/faithfulness, even unto death on the cross. Trebilco allows this is possible (see p. 77) but seems less than fully convinced. Note that in 2 Tim. 2.11-13 God himself is said to be pistos, which clearly means ‘faithful’ in this text.
Not surprisingly in a Gospel which has a purpose statement about believing Jesus is the Christ, the Son of God (in John 20), the very ‘pisteuo’ shows up an amazing 98 times in the Gospel and a further nine times in 1 John. This tells us a lot about the emphasis in this Gospel compared to the less frequent use of such language in the Synoptics. Here is an interesting contrast stressed by Trebilco (p. 117) whilst Paul usually uses the very pisteuo without an object of believing being mentioned, in John we have just the opposite. Out of 26 uses of the participle all but four go on to have a preposition such as ‘eis’ and an object of belief, usually Christ, is mentioned.
Trebilco’s conclusions are worth quoting: “While pist-terminology is found in Greco-Roman texts, ‘the believing ones’ is not a designation that is found in Greco-Roman religions or in Greco-Roman thought in general. Although faith is important in the OT and believer designations are found (even if rarely) in some Jewish texts, they have become so prominent in the NT that believer-designations are one of the very significant identifiers or defining characteristics in the NT.” (p. 118). Trebilco then goes on rightly to stress the connection between faith and salvation, so much so that faith can be said to be a soteriological category in the NT. Faith is a key condition for being saved, in the NT sense of the term. “Believing was both an initial response to the Gospel and an ongoing chracteristic of Christians.” (p. 120).