For all of you who do not believe in OSAS [Once Saved Always Saved] , can you please explain how a person who is already saved can then be damned?
This is not a direct answer to your question, just an 'OSAS' musing.
To be 'saved' means to be 'made whole'. Believers will not be made completely whole according to God's purpose until we receive our new bodies in heaven. Salvation (the noun) has a beginning, a middle and an end. We have been saved (a.k.a justified), we are being saved (a.k.a. sanctified) and we will be saved (a.k.a. glorified). Salvation has a 'sweep' to it. Therefore, OSAS technically should be "once having begun the process of being made whole always in the process of being made whole to the end'. Lets see, that would be, OHBTPOBMWAITPOBMWTTE. I don't say this to be a nerd, but there are a lot of verses that will trip up the youngsters in the word unless they are aware of this simple 'sweep' of salvation. Such as:
Whom having not seen, ye love; in whom, though now ye see him not, yet believing, ye rejoice with joy unspeakable and full of glory: Receiving the end of your faith, even the salvation of your souls. 1 Peter 1:8-9 [Peter is saying that the trials we go through down here will result in greater rejoicing when we are glorified---the fullness of our salvation. Unless we understand this, this verse might say to some that we are wishing and hoping about our salvation until the end]
The just shall live by faith. various [means those who have been justified [by faith] will continue to walk by faith through the sanctification stage of salvation]
and so on..