Ante-Nicene Fathers, Vol III:
Tertullian: Part II: Weak People Fall an Easy Prey to Heresy, Which Derives Strength from the General Frailty of Mankind.  Eminent Men Have Fallen from Faith; Saul, David, Solomon. The Constancy of Christ.

Chapter III.—Weak People Fall an Easy Prey to Heresy, Which Derives Strength from the General Frailty of Mankind. Eminent Men Have Fallen from Faith; Saul, David, Solomon. The Constancy of Christ.

It is usual, indeed, with persons of a weaker character, to be so built up (in confidence) by certain individuals who are caught by heresy, as to topple over into ruin themselves. How comes it to pass, (they ask), that this woman or that man, who were the most faithful, the most prudent, and the most approved 1858 in the church, have gone over to the other side? Who that asks such a question does not in fact reply to it himself, to the effect that men whom heresies have been able to pervert 1859 ought never to have been esteemed prudent, or faithful, or approved? This again is, I suppose, an extraordinary thing, that one who has been approved should afterwards fall back? Saul, who was good beyond all others, is afterwards subverted by envy. 1860 David, a good man “after the Lord’s own heart,” 1861 is guilty afterwards of murder and adultery. 1862 Solomon, endowed by the Lord with all grace and wisdom, is led into idolatry, by women. 1863 For to the Son of God alone was it reserved to persevere to the last without sin. 1864 But what if a bishop, if a deacon, if a widow, if a virgin, if a doctor, if even a martyr, 1865 have fallen from the rule (of faith), will heresies on that account appear to possess 1866 the truth? Do we prove the faith 1867 by the persons, or the persons by the faith?  No one is wise, no one is faithful, no one excels in dignity, 1868 but the Christian; and no one is a Christian but he who perseveres even to the end. 1869 You, as a man, know any other man from the outside appearance. You think as you see. And you see as far only as you have eyes. But says (the Scripture), “the eyes of the Lord are lofty.” 1870 “Man looketh at the outward appearance, but God looketh at the heart.” 1871 “The Lord (beholdeth and) knoweth them that are His;” 1872 and “the plant which (my heavenly Father) hath not planted, He rooteth up;” 1873 and “the first shall,” as He shows, “be last;” 1874 and He carries “His fan in His hand to purge His threshing-floor.” 1875 Let the chaff of a fickle faith fly off as much as it will at every blast of temptation, all the purer will be that heap of corn which shall be laid up in the garner of the Lord. Did not certain of the disciples turn back from the Lord Himself, 1876 when they were offended? Yet the rest did not therefore think that they must turn away from following Him, 1877 but because they knew that He was the Word of Life, and was come from God, 1878 they continued in His company to the very last, after He had gently inquired of them whether they also would go away. 1879 It is a comparatively small thing, 1880 that certain men, like Phygellus, and Hermogenes, and Philetus, and Hymenæus, deserted His apostle: 1881 the betrayer of Christ was himself one of the apostles. We are surprised at seeing His churches forsaken by some men, although the things which we suffer after the example of Christ Himself, show us to be Christians. “They went out from us,” says (St. John,) “but they were not of us. If they had been of us, they would no doubt have continued with us.” 1882

Footnotes

Usitatissimi, “most experienced.”

Demutare.

1 Sam. 18:8, 9.

1 Sam. xiii. 14.

2 Sam. xi.

1 Kings xi. 4.

Heb. iv. 15. [See p. 221, supra.]

[Here the word martyr means no more than a witness or confessor, and may account for what are called exaggerated statements as to the number of primitive martyrs. See Kaye p. 128.]

Obtinere.

Fidem, “The Creed.”

Major.

Matt. x. 22.

Jer. xxxii. 19.

1 Sam. xvi. 7.

2 Tim. ii. 19.

Matt. xv. 13.

Matt. xx. 16.

Matt. iii. 12.

John vi. 66.

A vestigiis ejus.

John 1:1, John 6:68, John 16:30.

John vi. 67.

Minus.

2 Tim. 1:15, 2 Tim. 2:17, 1 Tim. 1:20.

1 John ii. 19. [i.e., with the Apostolic Churches. See Cap. xx, infra.]