Other than to help convince some people that there MUST be a God...
In what way did ‘the bearing witness to Jesus inspire prophesying’?
In the apostle John’s vision he was told by an angel that “the bearing witness to Jesus is what inspires [literally, “is the spirit of”] prophesying.” (Re 19:10) The apostle Paul calls Christ “the sacred secret of God” and says that “carefully concealed in him are all the treasures of wisdom and of knowledge.” (Col 2:2, 3) This is because Jehovah God assigned to his Son the key role in the outworking of God’s grand purpose to sanctify His name and restore earth and its inhabitants to their proper place in His arrangement of things, doing this by means of “an administration at the full limit of the appointed times, namely, to gather all things together again in the Christ, the things in the heavens and the things on the earth.” (Eph 1:9, 10; compare 1Co 15:24, 25.) Since the fulfillment of God’s great purpose is all bound up in Jesus (compare Col 1:19, 20), then all prophecy, that is, all inspired messages from God proclaimed by his servants, pointed toward his Son. Thus, as Revelation 19:10 states, the entire “spirit” (the whole inclination, intent, and purpose) of prophecy was to bear witness to Jesus, the one Jehovah would make “the way and the truth and the life.” (Joh 14:6) This would be true not only of prophecy that preceded Jesus’ earthly ministry but also of prophecy subsequent thereto.—Ac 2:16-36.
...Purpose and Time of Fulfillment. Prophecy, whether prediction, simply inspired instruction, or reproof, served for the benefit of both those initially hearing it and those in all future periods who would put faith in God’s promises. For the original receivers, the prophecies assured them that the passing of years or centuries had not caused God to waver in his purpose, that he was holding firm to his covenant terms and promises. (Compare Ps 77:5-9; Isa 44:21; 49:14-16; Jer 50:5.) Daniel’s prophecy, for example, provided information that constituted an invaluable link between the close of the writing of the Hebrew or pre-Christian Scriptures and Messiah’s coming. Its forecast of world events, including the rise and fall of successive world powers, gave assurance to Jews living during the centuries of Persian, Greek, and Roman dominance (as well as to Christians thereafter) that there was no “blind spot” in God’s forevision, that their own times were indeed foreseen and that Jehovah’s sovereign purpose was still certain of fulfillment. It protected them against putting faith and hope in such passing world regimes with their transient power of control and enabled those faithful ones to direct their course with wisdom.—Compare Da 8:20-26; 11:1-20.
The fact that many prophecies were fulfilled in their own times convinced sincere ones of God’s power to carry out his purpose despite all opposition. It was proof of his unique Godship that he, and he alone, could foretell such events and bring them to pass. (Isa 41:21-26; 46:9-11) These prophecies also enabled them to become better acquainted with God, understanding more clearly his will and the moral standards by which he acts and judges, so that they might harmonize their lives with these.—Isa 1:18-20; 55:8-11.