It is a circular argument. Ask him what their basis is for using 360-day lunar years? If there is anything in the bible that indicates whether we should be using a 360-day year for our symbolic "years"? As the Society has often pointed out, an extra month had to be inserted "seven times, every nineteen years." That's because it actually takes 365+ days for the earth to complete an actual yearly cycle. Since the Society's scriptural recipe is based on the premise of 360-day years, they arrive at 1914, accounting for no zero-year. But if you take into account the extra month that had to be inserted every now and then, your premise would practically be based on a 365-day solar year. 365 · 7 = 2,555 years; 607 BCE - 2,555 years = 1949 (accounting for no zero-year, and notwithstanding the faulty 607 BCE date.) I would also like to point out that the Society's stubborn stand on 607 BCE is sort of ridiculous. And not for the reasons that are often cited: They could actually cling to that date on somewhat plausible grounds, on the fundamental fact alone that (and as confirmed by secular history), Judah was captured and rendered tributary by Nebachadnezzar circa 607/606 BCE. Many theologians and scholars affirm that this was when the prophetic "70 years of captivity" began. 20 years later, Jerusalem was finally destroyed, in 587/586 BCE, as affirmed by secular history. Though much of their argument regarding 1914 would still present some logical fallacies, their conjecture regarding the date would be far more plausible.
This is one of the problems that has lead to me to believe they do not have The Truthâ„¢ -they blindly cling to a date for the destruction of Jerusalem when they don't have to. There is a far more logical argument that harmonizes with secular history, but they would rather be stubborn than to ever admit they are wrong. I'm sorry to say, but this is the sort of superficially pious rhetoric that I've experienced all my life. Only in recent years had I become disillusioned enough to put my finger on it.
As for Christ - Jesus was given the prominence that a "Christian" denomination normally would - as our leader and our Lord (although nontrinitarian, as opposed to most denominations.) But in the past two or three decades, Christ's role and importance has been trumped more and more by the hierarchy of the Governing Buddy.