"Saints" in the bible is not a title reserved from some special Christians; it refers to all Christian believers.
We can only know with certainty if someone was truly a Christian after they have reposed, since until they repose, they might always apostasize, or demonstrate a lack of a living faith, which St. Paul and St. James warned are possible.
The conflation of asking those who have been glorified in Christ to pray for us to Christ, in whose immediate presence they are known to be, on account of innumerable confirmed miracles that concerns their relics, with liturgical worship and divine prayer, is a serious error made by some Protestants, which is fundamentally iconoclastic in character, and which is done in defiance of the known customs and practices of the early church, and which requires coercing the scriptural text into meaning what you say it means (for example, in Revelation).
However, even if your interpretation of Revelation were correct, and there was no mention of prayer to the saints in the New Testament, using that fact to argue against it would be logically fallacious, as an argument from silence. Indeed, the entire idea of the Regulative Principle of Worship favored by some Calvinists is an argument from silence.
It is particularly problematic when we ignore the theology of those who were responsible for the New Testament scriptural canon and the Nicene Creed, among whom we find active veneration of the saints, intercessory prayer, and the use of relics, including the identification of the true cross in Jerusalem by St. Helena the mother of Emperor Constantine, the liberator of Christians from the Diocletian persecution, who has been wrongfully accused by Landmark Baptists and Adventists of imposing Roman Catholicism on the world (which is untrue on every level, since the early Roman church was extremely conservative, barely participated at the Council of Nicaea, which was essentially a debate in what would become the Greek Orthodox Church, and supported St. Athanasius and Pope St. Alexander of Alexandria in their desire to anathematize Arius and uphold the doctrine of the Trinity, but due to the great distance between Rome and Nicaea, sent only two legates, compared to the 318 Greek, Syrian and Egyptian bishops who were in attendance at Nicaea, who made all the actual decisions, with St. Constantine merely presiding. And their beliefs also ignore, for example, how Emperor Constantine’s son Constantius was corrupted in faith by the evil Arian bishop Eusebius of Nicomedia, and was converted to Arianism, and he and all of his succesors except for “Julian the Apostate” (who was a Pagan of the neo-Platonist persuasion) were Arians, who actively persecuted Christian bishops who defended the Trinity, particularly St. Athanasius, who succeeded St. Alexander as Pope of Alexandria, and was ironically only allowed to return to Alexandria during the reign of Julian the Apostate.
Additionally, the bishop of Rome was not styled Pope until the sixth century, and a careful study of the history of the early church, setting aside certain accounts favored by Roman Catholics in polemical debates with Eastern and Oriental Orthodox, Anglican, Lutheran, Assyrian and Reformed theologians will reveal that Papal Supremacy in its present form did not appear until almost the eve of the schism in 1054 and was in many respects the innovation that led directly to the schism, when the Ecumenical Patriarch of Constantinoplerefused an uncanonical order from the Roman bishop. The Popes of Alexandria, like the other primates of the Orthodox Church, and more recently of the Anglican Communion and the Old Catholic churches, were the first among equals, but did not even have the authority to celebrate the divine liturgy outside of their diocese (and neither did the bishop of Rome - these restrictions were included in the Apostolic Canons and in the canons of the Ecumenical Councils).
The only distinguishing feature of the Roman Catholic Church which existed before the schism and remains until the present is clerical celibacy, which has existed in Rome for as long as anyone can remember, but which was never practiced in the Greek, Syrian, Egyptian, Armenian, Ethiopian, Georgian, Cypriot, Indian or Assyrian churches that made up the rest of Christendom at the time, and there is some reason to believe that it was not practiced everywhere in the West, but was rather specific to Rome and certain other Latin speaking dioceses closely connected to Rome, such as those of North Africa and Italy, but perhaps not in France or those areas where Gallican Rite liturgies were in use, as these liturgies bore significant influence from Eastern Orthodoxy (and only one remains in widespread use, the Ambrosian Rite in greater Milan, and it has been heavily Romanized, although conversely the Roman mass was also somewhat Gallicanized, in that the Old Roman Rite was extremely conservative, with a lack of antiphonal hymnody and a tendency to sing everything in monotone, which indeed remained the norm for the Low Mass until at least the ninth century, whereas antiphonal singing in the Greek tradition was introduced by St. Ambrose of Milan when he and many of his flock occupied a basillica that for some reason, the Christian emperor Theodosius wanted to give to the Arians to placate them, but this basillica had previously been given to the Church in Milan, and St. Ambrose and his followers would have rather perished than allow one of their major churches to be taken over by heretics, however, St. Ambrose introduced Greek-style antiphonal singing, in his words “Lest the people should perish in soulless monotony” and is also credited as the author of many of the oldest hymns in the Western Church.
The full eight-mode system of Gregorian chant was imported from the Byzantine church by St. Gregory the Great when he became Bishop of Rome (and was styled Pope, unlike his fourth century counterparts) for he had previously served as a legate to the Church in Constantinople, and had learned the Byzantine liturgy, and indeed made a great contribution to it and to the Roman liturgy by composing a new Presanctified liturgy which mostly displaced the older form of that liturgy and remains in use to the present in the Orthodox church, although in the Roman church, it was rewritten by Pope Pius XII in 1955 (I have heard that the Novus Ordo Missae reverted it to the old form, but I cannot confirm this, but there are other changes Pope Pius XII made to the liturgical services on Good Friday, Holy Saturday and Easter Sunday which remain).
