Galatians 5:3

"that he is a debtor to do the whole law." Against the statement, he says, that no longer does one receive anything from Christ, which is more grievous than ten thousand Gehennas. And such persons lay upon themselves a useless burden. For he who keeps …

There are some who serve the law to a certain extent without being circumcised; for many Romans in Judea served the law without circumcision.… Yet there is no one who is circumcised without being required to serve the whole law. He is a debtor, since …

When he says "bound," he is no longer speaking of the law as something unworthy but of a heavy burden which can be made lighter. There is one Lord, who is able to make it either heavy or light according to the choice of those …

And certain other (heretics), contentious by nature, (and) wholly uniformed as regards knowledge, as well as in their manner more (than usually) quarrelsome, combine (in maintaining) that Easter should be kept on the fourteenth day of the first month, according to the commandment of the law, on whatever day (of the week) it should occur. (But in this) they only regard what has been written in the law, that he will be accursed who does not so keep (the commandment) as it is enjoined. They do not, however, attend to this (fact), that the legal enactment was made for Jews, who in times to come should kill the real Passover. And this (paschal sacrifice, in its efficacy,) has spread unto the Gentiles, and is discerned by faith, and not now observed in letter (merely). They attend to this one commandment, and do not look unto what has been spoken by the apostle: "For I testify to every man that is circumcised, that he is a debtor to keep the whole law." In other respects, however, these consent to all the traditions delivered to the Church by the Apostles.

That you may not suppose that this is spoken from ill-will, I say not to you alone, he says, but to every one who receiveth circumcision, that he is a debtor to do the whole Law. The parts of the Law are linked one to the other. As he who from being free has enrolled himself as a slave, no longer does what he pleases, but is bound by all the laws of slavery, so in the case of the Law, if you take upon you a small portion of it, and submit to the yoke, you draw down upon yourself its whole domination. And so it is in a worldly inheritance: he who touches no part of it, is free from all matters which are consequent on the heirship to the deceased, but if he takes a small portion, though not the whole, yet by that part he has rendered himself liable for every thing. And this occurs in the Law, not only in the way I have mentioned, but in another also, for Legal observances are linked together. For example; Circumcision has sacrifice connected with it, and the observance of days; sacrifice again has the observance both of day and of place; place has the details of endless purifications; purifications involve a perfect swarm of manifold observances. For it is unlawful for the unclean to sacrifice, to enter the holy shrines, to do any other such act. Thus the Law introduces many things even by the one commandment. If then thou art circumcised, but not on the eighth day, or on the eighth day, but no sacrifice is offered, or a sacrifice is offered, but not in the prescribed place, or in the prescribed place, but not the accustomed objects, or if the accustomed objects, but thou be unclean, or if clean yet not purified by proper rules, every thing is frustrated. Wherefore he says, "that he is a debtor to the whole Law." Fulfil not a part, but the whole, if the Law is of force; but if it be not of force, not even a part.