3 For it is written that the just lives by faith. If you are just, and live by faith, if you truly believe in Christ, why, since you are about to be with Christ, and are secure of the Lord's promise, do you not embrace the assurance that you are called to Christ, and rejoice that you are freed from the devil? Certainly Simeon, that just man, who was truly just, who kept God's commands with a full faith, when it had been pledged him from heaven that he should not die before he had seen the Christ, and Christ had come an infant into the temple with His mother, acknowledged in spirit that Christ was now born, concerning whom it had before been foretold to him; and when he had seen Him, he knew that he should soon die.
Therefore, rejoicing concerning his now approaching death, and secure of his immediate summons, he received the child into his arms, and blessing the Lord, he exclaimed, and said, “Now let Your servant depart in peace, according to Your word; for my eyes have seen Your salvation;” assuredly proving and bearing witness that the servants of God then had peace, then free, then tranquil repose, when, withdrawn from these whirlwinds of the world, we attain the harbour of our home and eternal security, when having accomplished this death we come to immortality. For that is our peace, that our faithful tranquillity, that our steadfast, and abiding, and perpetual security.
Source: The Treatises of Cyprian (New Advent)