Q. Re: The Meaning of the Millennium. If the earth is re-populated only with believers after the 2nd Coming, and if believers can’t loose their salvation, then how can the 1000 years be a final test for mankind? In fact, what you are saying is that some will sink so low, they actually will loose their salvation and go to battle against The Lord. Would a believer do that – and can believers do that?
A. Eternal security is a blessing only given to believers during the Church Age. Following the rapture, salvation will be conditional upon obedience and faithfulness (Rev. 14:12) just as it was in the Old Testament . Remember, Daniel’s 70th Week is a return to Old Covenant conditions. That’s why a temple and animal sacrifice are necessary. My study on The Nature of Post Church Salvation explains this.
Children born during the Millennium will have to choose to be saved and will have to remain faithful to stay that way. As is the case today, some will choose salvation and others will not. What’s different is that some of those who choose salvation will fall away. As the millennium proceeds the number of unbelievers will increase until there will be enough for a massive army to be waiting when Satan is released at its end (Rev. 20:7-8).