Perseverance and falling away

Kaufmann Kohler states that it is never too late to return to God with sincere repentance, even on the day of death. The gates of repentance remain always open to the sinner, just as the sea is always open to anyone who wishes to cleanse himself.

Kaufmann Kohler (1843-1926), The Jewish Encyclopedia, vol. 10, s.v. 'Repentance' (New York: Funk & Wagnalls, 1901-1906) — Section on the never-too-late return (citing Ḳid. 40b and Pesiḳta)

Chrysostom says that although there is no second baptism, repentance does exist and has great power. It can free from the burden of sins and establish in safety one who is in danger, even someone baptized who has sinned greatly and reached the depth of wickedness.

John Chrysostom (c. 349-407), Homilies on the Epistle to the Hebrews, in Nicene and Post-Nicene Fathers, ser. 1, vol. 14 (ed. Philip Schaff; Edinburgh: T&T Clark, 1889) — Homily IX, section 8 (the exposition of Hebrews 6:4-6)

Augustine says no one stops persevering in the Christian purpose unless he is first led into temptation. If it is granted to him, according to his prayer, that he not be led into temptation, then by God's gift he certainly perseveres in the sanctification he received by God's gift.

Augustine of Hippo (354-430), On the Gift of Perseverance, in St. Augustin: Anti-Pelagian Writings, Nicene and Post-Nicene Fathers, ser. 1, vol. 5 (ed. Philip Schaff; New York: Christian Literature Publishing Co., 1886) — ch. 9 (When Perseverance is Granted to a Person, He Cannot But Persevere)

Sollier states that, as a power, final perseverance means the ensemble of spiritual means. By these means the human will is enabled to persevere unto the end if it duly cooperates.

Joseph Sollier, The Catholic Encyclopedia, vol. 11, s.v. 'Final Perseverance' (New York: Robert Appleton Company, 1911) — Section 'Definition and doctrine' (perseverance as power and as actual fact)

The Canons of Dort say believers do not totally fall from faith and grace or finally perish by their own merits or strength, but by God's free mercy. In themselves this is possible and would certainly happen, but with respect to God it is impossible, since his counsel, promise, call, Christ's merit, intercession, preservation, and the Spirit's sealing cannot fail.

The Synod of Dordt (1618-1619), The Canons of the Synod of Dort, in Philip Schaff, The Creeds of Christendom, vol. 3 (New York: Harper & Brothers, 1877) — Fifth Head of Doctrine (Of the Perseverance of the Saints), Article 8

Spurgeon states that Scripture does not teach that a man reaches his journey’s end without continuing to travel. One act of faith is not all, as if daily faith, prayer, and watchfulness were unnecessary. Rather, the righteous hold on their way, continuing in faith, repentance, prayer, and under the influence of God’s grace.

Charles Haddon Spurgeon (1834-1892), The Final Perseverance of the Saints, Metropolitan Tabernacle Pulpit, vol. 23 (preached June 24, 1877) — Exposition of the doctrine, after the reading of Job 17:9

Wesley reads Hebrews 6:6 as fact, not supposition. It describes those who wilfully cast away both the power and form of godliness, losing faith, hope, and love. Of these wilful total apostates he declares it impossible to renew them again to repentance—though renewed once—whether to the foundation or anything built on it.

John Wesley (1703-1791), Explanatory Notes upon the New Testament (1755); CCEL's 'Wesley's Notes on the Bible' — Note on Hebrews 6:6 (with the notes on 6:4-5)