I think a few modern evangelicals might regard this as heretical, being contrary to the pure penal substitutionary atonement or forensic justification. But he sure does seem to have a finger on precisely what Hebrews has to say.
[1.] Faith is indeed great and bringeth salvation, and without it, it is not possible ever to be saved. It suffices not however of itself to accomplish this, but there is need of a right conversation also. So that on this account Paul also exhorts those who had already been counted worthy of the mysteries; saying, “Let us labor to enter into that rest.” “Let us labor” (he says), Faith not sufficing, the life also ought to be added thereto, and our earnestness to be great; for truly there is need of much earnestness too, in order to go up into Heaven. For if they who suffered so great distress in the Wilderness, were not counted worthy of [the promised] land, and were not able to attain [that] land, because they murmured and because they committed fornication: how shall we be counted worthy of Heaven, if we live carelessly and indolently? We then have need of much earnestness.
And observe, the punishment does not extend to this only, the not entering in (for he said not, “Let us labor to enter into the rest,” lest we fail of so great blessings), but he added what most of all arouses men. What then is this? “Lest any man fall, after the same example of unbelief.” What means this? It means that we should have our mind, our hope, our expectation, yonder, lest we should fail. For that [otherwise] we shall fail, the example shows, “lest [&c.] after the same,” he says.