How can you tell one from another?
All I’ve seen, is y’all slapping each other on the back with such proclamations as, “See you in the clouds”.
If someone professes to be saved by faith, their changed lives will show it and generally their beliefs will align closely together.
If someone continues in a sinful lifestyle with no remorse over sin or desire to become more and more Christlike and please God, and does not show an interest in or understanding of spiritual matters, their profession of faith is rightly suspect.
But the final decision is God’s alone because He alone knows the heart. My opinion of whether they are truly saved or not is irrelevant and how I treat them is no different.