100% conclusively tell? (Yes, man cannot do that) But we both know Jesus saying there are indicators ("Ye shall know them by their fruit") + it's LDS who say the temple is man-made, whereas Christians point to the God-made temple--the person who is in Christ.
It's no coincidence that Paul brings up the body as a temple of the Holy Ghost in both letters to the Corinthians, and precedes one of the references with these two verses:
The spiritual man makes judgments about all things, but he himself is not subject to any man's judgment: "For who has known the mind of the Lord that he may instruct him?" But we have the mind of Christ. (1 Cor. 2:15-16)
Now I'm not saying "the spiritual man" knows who will be in heaven and who won't. What I am saying is that the Holy Ghost inside that person does know, and sometimes He gives illumination & discernment to "the spiritual man" to let him know that certain others are on the wrong pathway--the "wide is the road leading to destruction" reference Jesus made...and "destruction" is not a degree of glory!
I agree. :-) I'm surprised you believe in modern day revelation though. Pretty cool! This is better than an ecumenical thread!