Here is E. P. Sanders’ critique of Schweitzer, specifically, Schweitzer’s argument in Mysticism of Paul the Apostle. This is from Paul and Palestinian Judaism. (I’ve included Sanders’ footnotes because they have a wealth of information).
This is not to say that Schweitzer’s position is completely correct. It is oversimplified in one minor way and in one major way. It is possible, for one thing, to find some passages in which ‘faith’, if not ‘righteousness by faith’, is related to ethics,48 although one must note that Paul generally works out his ethical statements on the basis of the believers’ life in the Spirit. But more important—and this is basically what is wrong with Schweitzer’s theory as a whole—Schweitzer did not see the internal connection between the righteousness by faith terminology and the terminology about life in the Spirit, being in Christ and the like (terminology which here will be called ‘participationist’,49 which seems better than the controversial term ‘mystical’), a connection which exists in Paul’s own letters. Thus Schweitzer did not note that besides saying that one becomes one body with the Lord in the sacraments (1 Cor. 10:17; 12:13), Paul also wrote that the Spirit is received through faith (Gal. 3:1–5).50
48See Gal. 5:6 and perhaps Rom. 14:23. In discussing Gal. 5:6 (‘faith working through love’) and 5:22–24 (the fruits of the Spirit), Bornkamm (Paul, p. 153) comments that ‘justification is [the] precondition’ for the fruits of the Spirit. This, however, is just what Paul does not say, and it is precisely in Gal. 5:5 that righteousness or justification is said to be expected in the future. Thus Gal. 5:6 does not lead to the conclusion that ethics are connected with the terminology ‘righteousness by faith’ as such. In Rom. 14:23 (‘whatever does not proceed from faith is sin’), the meaning of ‘faith’ is probably simply ‘conviction’ (see the NEB and Whiteley, Theology of St Paul, p. 59; cf. the Jerusalem Bible: ‘done in bad faith’), so that again ethics are not based on being justified by faith.
49Käsemann argued that ‘participation’ is too weak, since it does not sufficiently describe the power of Christ’s lordship which seizes believers: ‘The Lord’s Supper’, Essays, p. 124. It nevertheless seems the best general term. So also Whiteley, Theology of St Paul, e.g. pp. 130, 152, 154 (‘the main consistent set of symbolism expresses participation’). Note also Tannehill’s terms: ‘corporate patterns of thought (Dying and Rising, p. 24), ‘inclusive patterns of thought’ (p. 24).
Source: E. P. Sanders, Paul and Palestinian Judaism: A Comparison of Patterns of Religion (Philadelphia: Fortress Press, 1977), 440.