Eternal Security

I am not here to judge; I really want to learn. Some questions for Once Saved, Always Saved people.

I know it is not a license to sin and that sin is completely discoraged but assuming someone is truly saved it would literally mean they could live their life any way they want, adopt any theology as well as outright deconvert and not repent when they sin for any reason.

If you want to say their capability of doing this means they were never saved to begin with, then how do any of us know what we are capable of unless we live long enough or are in a certain situation? And if we never find out how can anyone know they are saved?

If would mean that as long as someone was truly saved, even for the briefest instant, it does not matter if they are a Christian when they die. They only have to have been a Christian at some point in their life to go to heaven. Almost all people get saved as children, so they would only have to have gotten saved then and their future beliefs do not matter.

If they were not saved, then how are they to know any future attempt to get saved would work? And even then, as long as it was true salvation, any future change in their beliefs after then would not affect whether or not they go to heaven when they die.

It would mean that most people who go to heaven, the new creation or paradise, when they die are not Christians.

If salvation can be chosen at all, although it would take some time, why do we not let people who are about to get saved know they are about to make an irreversible decision? Even if it makes them unable to go to hell, do we really want to risk tricking people into converting? Is it even likely God would make salvation even able to work like that?

Can a person really get saved but not adhere to anything Christian the rest of the time after?