Why do so many people deny that Jesus has already come once?

Les Feldick illustrates this denial through an exchange between an evangelical pastor and a Jewish rabbi. The pastor tried to convince the rabbi that Christ was here the first time and would be coming again, but the rabbi said, "No, He's never been here before. He's coming the first time when He comes." Finally the rabbi suggested putting it on hold and asking Him when He gets here if He's been here before. Les says this is the whole mentality of so many people: they cannot reckon the fact that He has been here. He was rejected, went back to glory, but He's coming again, and we're getting close. Les then notes that Paul in verse 15 refers to this, contrasting the reconciliation poured out on the Gentile world with what will happen to Israel when God comes back to fulfill His promises, which will be life from the dead. Israel is currently dead among the nations, not a viable entity, but is coming back—evidenced by the little nation of Israel constantly in world news—because they are God's people being prepared for His soon return.