Christians cannot be reasonably assured of eternal salvation.

I'm probably meant to be wrapping up my arguments at this stage, but I'm afraid I will need to present new ones. My opponent has reiterated his points from John 6:38-40. I assert that this portion of Biblical scripture is talking about gaining salvation. Whilst on the surface it may look like a promise is being made that salvation cannot be lost, but this cannot be true in light of the following two points; 1) Hebrews 10:26-31 If we deliberately keep on sinning after we have received the knowledge of the truth, no sacrifice for sins is left, but only a fearful expectation of judgement and of raging fire that will consume the enemies of God. Anyone who rejected the law of Moses died without mercy on the testimony of two or three witnesses. How much more severely do you think someone deserves to be punished who has trampled the Son of God underfoot, who has treated as an unholy thing the blood of the covenant that sanctified them, and who has insulted the Spirit of grace? For we know him who said, "It is mine to avenge; I will repay," and again, "The Lord will judge his people." It is a dreadful thing to fall into the hands of the living God. 2) Lucifer, Adam and Eve were all perfect and sinless creatures that made the choice to sin. I do not feel my opponent has done anything to explain or deal with this particular issue. Instead he tries to reassure everyone via scripture that their salvation is secure. This is not a debate on Calvinism vs Arminianism where the issue is if you can lose your salvation whilst here on Earth. This debate is about the eternity existing 100 billion years from now and if salvation can be lost at that time. 3) Revelation 20:1-3 followed by Revelation 20:7-8 And I saw an angel coming down out of heaven, having the key to the Abyss and holding in his hand a great chain. He seized the dragon, that ancient serpent, who is the devil, or Satan, and bound him for a thousand years. He threw him into the Abyss, and locked and sealed it over him, to keep him from deceiving the nations any more until the thousand years were ended. After that, he must be set free for a short time. When the thousand years are over, Satan will be released from his prison and will go out to deceive the nations in the four corners of the earth - Gog and Magog - and to gather them for battle. In number they are like the sand on the seashore. So the scene in the above picture is that peace has existed in Heaven and Earth for 1000 years, all have bowed down and worshiped God as the only true King and salvation is assured for all. Then Satan is loosed to deceive as many people as he can. So all the people that choose to fight along side Satan were once saved and now they no longer are. How does this stack up with the promise of Jesus in John chapters 6 and 10? My presumption (which I should have spelled out more clearly) was that a Christian has made it through life, made it through Armageddon, made it through the tribulation and again through the final battle between good and evil. At some point after this, with an eternity on your hands how could you not at some point sin once again? It wasn't my intention to focus on this point, but my opponent made the choice to use scriptures reassuring one of salvation, thinking about it now what other evidence could have have given? none I think. I thank you all for your patience with me, especially my opponent who has done a good job of making me think and do research. I wasn't intending on such a Bible centric debate and if that is not to your taste then I sincerely apologise.