"OBJECTIONS CONSIDERED
Objection: Those who keep the seventh-day Sabbath rely mainly on the Old Testament to prove their doctrine.
Answer: We go to both the Old and the New Testament; for they support each other, and the New Testament would have but little force without the Old. 
1. The New-Testament Scriptures are largely made up of references to, and quotations from, the Old;
2. The Old-Testament Scriptures testify of Christ, and without them it would be difficult to show that Christ was the Messiah;
3. Christ commands us to search them (John 5:39), and says, "It is written, Man shall not live by bread alone, but by every word that proceedeth out of the mouth of God" (Matt. 4:4);
4. They are all the Scriptures that the apostles and the primitive church had for years;
5. Those who searched them in apostolic times, were said to be more noble than those who did not (Acts 17:11)." D.T. Bordeaux