There is no contradiction between Paul’s act in circumcising Timothy (Acts 16:3) and his doctrine that circumcision invalidated a Gentile’s standing in the faith. Timothy was a Jew, and as such, stood in a natural relation to circumcision, which was enjoined upon Abraham as a token of the covenant under which his seed, after the flesh, were nationally chosen. Paul’s doctrine and Paul’s general course were misunderstood by the Jews. They represented him as a destroyer of the law, and a preacher of Mosaic disobedience, whereas his great contention was that it was the Gentiles who had nothing to do with Mosaic institutions, and that any justified Gentile seeking justification by the law or by circumcision, had “fallen from grace.” Paul circumcised Timothy at Lystra, “because of the Jews who were in that quarter,” — not to gain their favour, but to deprive them of the occasion of helping the slander that was current elsewhere, that he “taught all the Jews which were among the Gentiles to forsake Moses, saying they ought not to circumcise their children, neither to walk after the customs” (Acts 21:21). Afterwards, the Jewish brethren at Jerusalem, who knew the nature of Paul’s objections to the law as affecting only Gentile believers, gave him this advice: “We have four men who have a vow on them: them take and purify thyself with them . . . and all may know that those things whereof they were informed concerning thee are nothing,but that Thou thyself walkest orderly and keepest the law” (Acts 21:23, 24). Paul acted on this advice, and thus gave public illustration of the true nature of his attitude. (Robert Roberts, The Christadelphian 1882 p 128).
The Origin of the Organic World – Part One