Dear Hildebrand:
It is a dogma of the faith that immediately after we die there is a Particular Judgment (apart from the Great White Throne Judgment where are souls are reunited with our resurrected bodies). Since this is dogma it must be believed by all Catholics. Catholic or not, the Church has always taught this.
St. Augustine said:
For with respect to that which he (Victor] most correctly and very soundly holds, namely, that souls are judged when they depart from the body, before they come to that judgment which must be passed on them when reunited to the body and are tormented or glorified in that same flesh which they here inhabited... (De anima et ejus origine, 11, n.8.)
If this is not true, then the only other possibility is what is called "soul sleep" where the soul is unconscious until the Resurrection. There were a few heretics who held this view:
Among heretics the particular judgment was denied by Tatian and Vigilantius. The Hypnopsychites and the Thnetopsychites believed that at death the soul passed away, according to the former into a state of unconsciousness, according to the latter into temporary destruction. They believed that souls would arise at the resurrection of the body for judgment. This theory of "soul slumber" was defended by the Nestorians and Copts, and later by the Anabaptists, Socinians, and Arminians. Calvin (Inst. III, 25) holds that the final destiny is not decided till the last day.
This heresy is carried on into Protestant circles by the Anabaptists, Socinians, and Arminians. Calvin also alludes to this in that he taught that the judgment of eternal destiny was not until the end of time.
But, the Church Fathers taught that the judgment of the individual person as to his eternal destiny was immediately after death (the Particular Judgment).
As for the Bible, there is no indication of "soul sleep". There is, however, indications of a judgment immediately after death, and even some examples.
The Catholic Encyclopedia explains:
There is no text of which we can certainly say that it expressly affirms this dogma but there are several which teach an immediate retribution after death and thereby clearly imply a particular judgment. Christ represents Lazarus and Dives as receiving their respective rewards immediately after death. They have always been regarded as types of the just man and the sinner. To the penitent thief it was promised that his soul instantly on leaving the body would be in the state of the blessed: "This day thou shalt be with me in Paradise" (Luke 23:43). St. Paul (2 Corinthians 5) longs to be absent from the body that he may be present to the Lord, evidently understanding death to be the entrance into his reward (cf. Philemon 1:21 sq.). Ecclesiasticus 11:28-29 speaks of a retribution at the hour of death, but it may refer to a temporal punishment, such as sudden death in the midst of prosperity, the evil remembrance that survives the wicked or the misfortunes of their children. However, the other texts that have been quoted are sufficient to establish the strict conformity of the doctrine with Scripture teaching. (Cf. Acts 1:25; Revelation 20:4-6, 12-14)
The Catholic Catechism states:
1021 Death puts an end to human life as the time open to either accepting or rejecting the divine grace manifested in Christ. (Cf. 2 Tim 1:9-10.) The New Testament speaks of judgment primarily in its aspect of the final encounter with Christ in his second coming, but also repeatedly affirms that each will be rewarded immediately after death in accordance with his works and faith. The parable of the poor man Lazarus and the words of Christ on the cross to the good thief, as well as other New Testament texts speak of a final destiny of the soul--a destiny which can be different for some and for others. (Cf. Lk 16:22; 23:43; Mt 16:26; 2 Cor 5:8; Phil 1:23; Heb 9:27; 12:23)
1022 Each man receives his eternal retribution in his immortal soul at the very moment of his death, in a particular judgment that refers his life to Christ: either entrance into the blessedness of heaven-through a purification or immediately, -- or immediate and everlasting damnation.
- At the evening of life, we shall be judged on our love.
I hope this helps to understand the issue.
God Bless,
Bro. Ignatius Mary