The Gospel of God to which the Apostle Paul declared himself to be separated, was the Gospel. "Which He had promised afore by His prophets in the Holy Scriptures." (Romans 1:2) Literally, the Gospel which He had before announced or preached. This shows us that the Old Testament contains the Gospel, and also that the Gospel in the Old Testament is the same Gospel that is in the New. It is the only Gospel that the apostle preached.
That being the case, it should not be thought strange for men to believe the Old Testament, and to refer to it as of equal authority with the New Testament. We read that: "[God] preached beforehand the Gospel unto Abraham, saying, In you shall all nations be blessed." (Galatians 3:8)
The Gospel preached to the people when Paul lived, was the same Gospel that was preached unto the ancient Israelites.
"For unto us was the gospel preached, as well as unto them." (Hebrews 4:2)
Moses wrote of Christ; and so much of the Gospel is to be found in his writings that a man who does not believe what Moses wrote, cannot believe in Christ.
"For had you believed Moses, you would have believed me, for he wrote of me. But if you believe not his writings, how shall you believe my words?" (John 5:46-47)
"To Him gave all the prophets witness, that through His name whosoever believes in Him shall receive remission of sins." (Acts 10:43)
Paul had only the Old Testament when he went to Thessalonica, "and three Sabbath days reasoned with them out of the Scriptures, Opening and alleging, that Christ must needs have suffered, and risen again from the dead." (Acts 17:2)
Timothy had nothing in his childhood and youth but the Old Testament writings, and the apostle wrote to him: "Continue in the things which you have learned and have been assured of, knowing of whom you have learned them; And that from a child you have known the Holy Scriptures, which are able to make you wise unto salvation through faith which is in Christ Jesus." (2 Timothy 3:14-15)
Then go to the Old Testament with the expectation of finding Christ and His righteousness there, and you will be made wiser unto salvation. Do not discriminate between Moses and Paul, between David and Peter, between Jeremiah and James, between Isaiah and John.--Present Truth, June 21, 1894.
E.J. Waggoner