Ephesians 1:10
10 That in the dispensation of the fulness of times he might gather together in one all things in Christ, both which are in heaven, and which are on earth; even in him:.../
Have you ever heard the Dispensation of Times taught on? This in Ephesians sounds like their talking about the final Dispensation of time. The fullness of the dispensation of times. In other words, when it is complete.
Given that God is outside these time realms, I don't see why He couldn't take someone back in Time. After all, He IS God. I think you reject acceting that it is even possible because your church hasn't taught on it?