Helvidius has shown himself too ignorant, in saying that Mary had several sons, because mention is made in some passages of the brothers of Christ. - John Calvin

Primo meretur eorum perdita obstinatio et indomabilis, ut immensa miseriarum congerie sine fine et modo oppressi omnes exhilarent suis malis, nemo autem eorum misereatur. (Their [the Jews] depraved and indomitable obstinacy merits that none of them be pitied, as they all delight in their evils while being oppressed by a great mass of miseries without end or measure.)

The name of Christ is used here instead of the Church, because the similitude was intended to apply—not to God's only-begotten Son, but to us. It is a passage that is full of choice consolation, inasmuch as he calls the Church Christ; for Christ confers upon us this honour —that he is willing to be esteemed and recognised, not in himself merely, but also in his members. Hence the same Apostle says elsewhere, (Eph. i. 23,) that the Church is his completion, as though he would, if separated from his members, be incomplete.

For we are not all equally afflicted with the same disease or all in need of the same severe cure. This is the reason why we see different persons disciplined with different crosses. The heavenly Physician takes care of the well-being of all his patients; he gives some a milder medicine and purifies others by more shocking treatments, but he omits no one; for the whole world, without exception, is ill (Deut 32:15).