1 Therefore you are without excuse, whoever you are, when you judge someone else. For on whatever grounds you judge another, you condemn yourself, because you who judge practice the same things. 2 Now we know that God’s judgment is in accordance with truth against those who practice such things. 3 And do you think, whoever you are, when you judge those who practice such things and yet do them yourself, that you will escape God’s judgment? 4 Or do you have contempt for the wealth of his kindness, forbearance, and patience, and yet do not know that God’s kindness leads you to repentance? 5 But because of your stubbornness and your unrepentant heart, you are storing up wrath for yourselves in the day of wrath, when God’s righteous judgment is revealed! 6 He will reward each one according to his works: 7 eternal life to those who by perseverance in good works seek glory and honor and immortality, 8 but wrath and anger to those who live in selfish ambition and do not obey the truth but follow unrighteousness.
Shabbat 153aBabylonian Talmud
We learned there in a mishna that Rabbi Eliezer says: Repent one day before your death. Rabbi Eliezer’s students asked him: But does a person know the day on which he will die? He said to them: All the more so this is a good piece of advice, and one should repent today lest he die tomorrow; and by following this advice one will spend his entire life in a state of repentance. And King Solomon also said in his wisdom: “At all times your clothes should be white, and oil shall not be absent from upon your head” (Ecclesiastes 9:8), meaning that a person always needs to be prepared.
Notes and References
"... That man should always be in the attitude and spirit of repentance is the meaning of the saying, "Repent one day before thy death" (Pirkei Abot 2:10); Shabbat 153a, since no man knows but that this day is his last, therefore repent today. For this reason the petition that God will bring his worshippers back in perfect repentance has its place among the first in the Daily Prayer (Tefillah; Singer, p. 46; Baer, p. 90) immediately preceding the petition for forgiveness ..."
Moore, George Foot Judaism in the First Centuries of the Christian Era (p. 156) Hendrickson, 1997