31. If you continue in my word. Here Christ warns them, in the first place, that it is not enough for any one to have begun well, if their progress to the end do not correspond to it; and for this reason he exhorts to perseverance in the faith those who have tasted of his doctrine. When he says that they who are firmly rooted in his word, so as to continue in him, will truly be his disciples, he means that many profess to be disciples who yet are not so in reality, and have no right to be accounted such. He distinguishes his followers from hypocrites by this mark, that they who falsely boasted of faith give way as soon as they have entered into the course, or at least in the middle of it; but believers persevere constantly to the end. If, therefore, we wish that Christ should reckon us to be his disciples, we must endeavor to persevere.