In preaching to the Thessalonians, Paul appealed to the Old Testament prophecies concerning the Messiah. Christ in His ministry had opened the minds of His disciples to these prophecies; "beginning at Moses and all the prophets, He expounded unto them in all the Scriptures the things concerning Himself." Luke 24:27. Peter in preaching Christ had produced his evidence from the Old Testament. Stephen had pursued the same course. And Paul also in his ministry appealed to the scriptures foretelling the birth, sufferings, 222 death, resurrection, and ascension of Christ. By the inspired testimony of Moses and the prophets he clearly proved the identity of Jesus of Nazareth with the Messiah and showed that from the days of Adam it was the voice of Christ which had been speaking through patriarchs and prophets.

Da Paulus prædikede for tessalonikerne, henviste han dem til de gammeltestamentlige profetier om Messias. Kristus havde under sin gerning åbnet sine disciples øjne for forståelse af disse profetier: "idet han gik ud fra Moses og alle profeterne, udlagde han for dem, hvad der i alle skrifterne handlede om ham." Luk. 24,27. Da Peter forkyndte Kristus, fremdrog han sine beviser fra det gamle Testamente. Stefanus havde fulgt samme fremgangsmåde. Og også Paulus benyttede ved sin forkyndelse de skrifter, der forudsagde Kristi fødsel, død, opstandelse og himmelfart. Gennem Moses og profeternes inspirerede vidnesbyrd beviste han klart, at Jesus fra Nazaret var Messias, og viste dem, at fra Adams tid var det Kristi røst, der havde lydt ved patriarkerne og profeterne.