John Calvin Commentary Psalms 69:28

"Let them be blotted out of the book of life, And not be written with the righteous." — Psalms 69:28 (ASV)

Let them be blotted out from the book of the living. This is the final imprecation, and it is the most dreadful of all; but it nevertheless consistently follows the persistent impenitence and incorrigible obduracy of which the Psalmist has spoken earlier. After having taken away from them all hope of repentance, he pronounces eternal destruction upon them, which is the clear meaning of the prayer that they might be blotted out of the book of the living; for all those will inevitably perish who are not found written or enrolled in the book of life.

This is indeed a figurative way of speaking, but it is one well suited to our limited understanding, as the book of life is nothing other than the eternal purpose of God, by which he has predestined his own people to salvation. God, certainly, is absolutely immutable; furthermore, we know that those who are adopted into the hope of salvation were written before the foundation of the world (Ephesians 1:4). But since God’s eternal purpose of election is incomprehensible, it is said, as an accommodation to the imperfection of human understanding, that those whom God openly, and by manifest signs, enrolls among his people, are written.

On the other hand, those whom God openly rejects and casts out of his Church are, for the same reason, said to be blotted out. Since David therefore desires that the vengeance of God may be manifested, he rightly speaks of the reprobation of his enemies in language suited to our understanding. It is as if he had said: “O God! Do not count them among the number or ranks of your people, and do not let them be gathered with your Church. Instead, show by destroying them that you have rejected them. And although they occupy a place for a time among your faithful ones, finally cut them off, to make it manifest that they were aliens, though they were mixed with the members of your family.” Ezekiel uses similar language when he says,

And mine hand shall be upon the prophets that see vanity, and that divine lies: they shall not be in the assembly of my people, neither shall they be written in the writing of the house of Israel (Ezekiel 13:9).

However, what is spoken by the Apostle John (1 John 2:19) remains true: that none who have once truly been the children of God will ever ultimately fall away or be completely cut off. But as hypocrites presumptuously boast that they are the chief members of the Church, the Holy Spirit well expresses their rejection by the figure of their being blotted out of the book of life. Moreover, it is to be noted that, in the second clause, all the elect of God are called the righteous, for as Paul says in 1 Thessalonians 4:3, 4, 7,

This is the will of God, even our sanctification, that every one of us should know how to possess his vessel in sanctification and honor: for God hath not called us unto uncleanness, but unto holiness (1 Thessalonians 4:3, 4, 7).

And the climax that the same Apostle uses in the 8th chapter of his Epistle to the Romans, at the 30th verse, is well known:

Whom he did predestinate, them he also called; and whom
he called, them he also justified; and whom he justified,
them he also glorified (Romans 8:30).