He was not referring to eternal life, he was referring to the physical body being saved... read it in context.
I don't think Jesus was talking about salvation of the physical body ... He was talking about the last day. The only way we can understand salvation is at the moment of the judgement. Why is it that there are so many people who believe that salvation is something they can grasp as if it were an object? People can be saved, and after been saved of whatever they were saved, not be saved about something else.
Jud 1:4 (ESV) For certain people have crept in unnoticed who long ago were designated for this condemnation, ungodly people, who pervert the grace of our God into sensuality and deny our only Master and Lord, Jesus Christ.
5 Now I want to remind you, although you once fully knew it, that Jesus, who saved a people out of the land of Egypt, afterward destroyed those who did not believe.
There is not a final salvation. Even when everybody will be saved at the last moment of what is coming, they could lose their lives if they do not stay obedient. If somebody can hold the life that would mean they are gods ... No human been can hold life by itself, it is God who gives us life, and the same way, like israelites, He can take it back ... and no more salvation.