Seventh-Day Adventism sprang out of a false prediction of the Second Coming. William Miller (1782–1849), a Baptist minister, had interpreted the 2,300-day prophecy of Daniel 8:14 as indicating that the year of Christ’s return to Earth would be 1843 (later revised to 1844). He ignored the New Testament warning that "no one knows about that day or hour" (Matt. 24:36).
When Christ failed to return, Miller withdrew from setting dates, but some of his followers were not so willing to confess error. They insisted the end was imminent. They re-interpreted the prophecy to mean Christ’s heavenly ministry had entered a new phase in 1844. Several leaders of this group, through a series of "theological insights" confirmed by the visions of Ellen Gould White (1827–1915), who was thought a prophetess, formed the Seventh-day Adventist denomination.
One of these "theological insights," that Christians are required to observe the Jewish Sabbath, led Seventh-day Adventists to conclude they were God’s movement for the last days. Just as the Reformers believed they had recovered the principle of justification by faith, Seventh-day Adventists believed they have rescued God’s Law from Catholic corruptions.
Even though Seventh-day Adventism had much of its origins in Baptist theology, it is considered heterodox by Fundamentalists and Evangelicals, many of whom consider Seventh-day Adventism a non-Christian cult because of its doctrinal deviations.
The first theological point that a Seventh-day Adventist is likely to challenge a Catholic on is the belief that the Jewish Sabbath is still binding on Christians. This is a central tenet of Adventist teaching. In Adventist theology, the Catholic Church is the Great Whore of Babylon described in Revelation 17 because it has trampled on God’s commandments by changing the observance of the Sabbath to Sunday. In fact, Seventh-day Adventists teach that "Sunday-keeping" will be the mark of the beast and will be evident when the divine com¬mand goes forth to observe the Sabbath.
This divine command is carried by the angel from Revelation 14:7 who says, "Worship him who made the heavens, the earth, the sea and the springs of water." Since this verse points to God as Creator, and since the Sabbath is a memorial of creation, Adventists conclude this means the angel will make it clear it is idolatrous to observe Sunday worship.
The strongest verse refuting Adventism on this point is Colossians 2:16: "Therefore let no one pass judgment on you in questions of food and drink or with regard to a festival or a new moon or a sabbath." Seventh-day Adventists claim Paul was talking about the Jewish ceremonial Sabbaths, but the majority of scholars, Protestant and Catholic, agree Paul was referring to yearly, monthly, and weekly observances, including the weekly Sabbath. A similar verse can be found in Galatians 4:10.
There is evidence for the Catholic Church’s teaching that the early Church replaced the Jewish Sabbath with Sunday to commemorate the Resurrection of Christ from the dead on the first day of the week. This day was called the "Lord’s Day" (Rev. 1:10). It is the day on which Christians gathered to "break bread" (Acts 20:7) and the day on which the Corinthians were to set aside money for the collection (1 Cor. 16:2).
Ignatius of Antioch (c. 110) wrote, "Those who walk in the ancient practices attain to newness of hope, no longer observing the Sabbath, but fashioning their lives after the Lord’s Day on which our life also arose through him, that we may be found disciples of Jesus Christ, our only teacher" (Letter to the Magnesians).
In the middle of the second century Justin Martyr explained why Sunday is the day Christians observe: "Sunday is the day on which we all gather in a common assembly, because it is the first day, the day on which God, changing darkness and matter, created the world, and it is the day on which Jesus Christ our Savior rose from the dead" (First Apology).
A Seventh-day Adventist will counter with the argument that the early Church apostatized from Christ’s teaching after the death of the apostles. This argument is untenable. The Fathers were a theologically conservative lot, willing to suffer martyrdom rather than compromise the smallest portion of the faith. Besides, accusing the Church of general apostasy contradicts Christ’s teaching that the "gates of hell will not prevail against it" (Matt. 16:18).
A second doctrine which Seventh-day Adventists are likely to challenge Catholics on is the doctrine of the extinction of the soul. Adventists teach that the soul of man is not conscious after death, but that it enters into a kind of sleep when the body dies. When the resurrection occurs, bodies and souls will be revivified. Just people will enter into life everlasting, while the wicked will be punished by fire until they die and cease to exist once again. A corollary to the doctrine of the extinction of the soul is the doctrine that the punishment of hell is not eternal. This doctrine Adventists share with Jehovah’s Witnesses and Herbert W. Armstrong’s Worldwide Church of God.
Paul writes in Philippians 1:23–24, "I am torn between the two: I desire to depart and be with Christ, which is better by far; but it is more necessary for you that I remain in the body." He is saying he would prefer to be martyred and be with Christ, but he realizes it is necessary for him to remain alive in order to spread the gospel by his preaching. If the soul "sleeps" (ceases to exists, really) at death, how could it be "better by far" to be martyred rather than continue to have fruitful labor here on Earth?
Adventists are fond of quoting Ecclesiastes 3:19–21 and other Old Testament passages which seem to indicate there is no afterlife. These passages are either written from a human point of view, or they are based on the incomplete revelation the Israelites had concerning the afterlife. It was only when Jesus brought "life and immortality to light through the gospel" (2 Tim. 1:10) that it became clear what the state of the soul is after death.
The Bible teaches the eternal duration of hell. Jesus says in Matthew 25:46, "They will go away to eternal punishment, but the righteous to eternal life:" If Adventists concede eternal life is never-ending, they must also concede eternal punishment is never-ending.
A last point: It is a good tactic to stress the beliefs Adventists and Catholics have in common, such as the Incarnation, Resurrection, and Second Coming of Christ. Another area where Adventists agree with Catholics is that a "born again" believer can be lost through disobedience to God. This is in contrast to the eternal security doctrine held by most Fundamentalists. Explaining the areas of agreement will help diffuse some of the misconceptions the Adventists have concerning the Catholic faith.