When Jesus knew in himself that his disciples murmured at it, he said unto them, Doth this offend you?
Note 11 at Joh 6:61: This scripture, as well as Mt 15:12, shows that people will be offended by the Gospel. As much as possible, however, we should make sure that it is not we who are offensive. But we cannot labor under the deception that everyone will receive the Gospel even if the truth was presented properly. We know that Jesus represented His Father perfectly, and yet most people rejected His message.
In these two instances when Jesus realized He had offended the listeners, He didn't apologize and try to make concessions to gain their acceptance. Instead, He got harder. This hard message of commitment is not only beneficial to those who receive it, but it serves a dual purpose in that it exposes the "tares among the wheat" (Mt 13:25, see note 1 at Mt 13:37).