Patristic Wisdom: Looking to the Twenty-First Sunday after Pentecost

Therefore, since a promise remains of entering His rest, let us fear lest any of you seem to have come short of it. For indeed the gospel was preached to us as well as to them; but the word which they heard did not profit them, not being mixed with faith in those who heard it.… There remains therefore a rest for the people of God. For he who has entered His rest has himself also ceased from his works as God did from His. Let us therefore be diligent to enter that rest, lest anyone fall according to the same example of disobedience. For the word of God is living and powerful, and sharper than any two-edged sword, piercing even to the division of soul and spirit, and of joints and marrow, and is a discerner of the thoughts and intents of the heart. And there is no creature hidden from His sight, but all things are naked and open to the eyes of Him to whom we must give account. (Heb 4:1–2, 9–13)

David promised us, he is saying, that there is a different rest; so let us be keen to attain to it so as not to suffer a fate similar to theirs. Hearing the words does not suffice for salvation; accepting it in faith is necessary, and holding it firm. After all, what benefit was God’s promise to those who received it, but did not receive it faithfully, trust in the power of God or, as it were, associate closely with God’s words?

He called the rest sabbath rest since on the seventh day God rested from all the works He had performed, whereas in the next world life will be free of grief, proof against labor, and rid of cares. So he called the freedom from bodily works sabbath rest, as the sequel indicates. As the God of all on the sixth day completed the whole of creation, and on the seventh He rested from creating, so those departing this life and moving to that one will be rid of the present labors. The Law required Jews to refrain from bodily works on the sabbath, and to devote attention to souls alone.… The person in the grip of sloth and not desirous of enjoying the promised goods will be liable to the accusations of those who were disobedient.

Then he shows the fearful judgement: nothing can escape that incorruptible Judge; He knows everything precisely, even the movements of our very thoughts. He knows what is done under cover of darkness, He knows what is committed in secret, the wicked counsels of the soul did not elude Him, what is hidden is laid bare to Him.… Now, if it was not just to them but also to everyone of us that the divine apostle wrote this. So it behooves us to consider that divine judgement constantly, be afraid and tremble, keep the divine commandments assiduously, and look forward to the promised rest. May we attain it in Christ, to whom with the Father and the all-holy Spirit be glory and magnificence, now and forever, for ages of ages. Amen.

Theodoret of Cyrus, Commentary on Hebrews 4