You are wrong. They deal DIRECTLY with the concept of salvation being eternal. Either the Christian has been regenerated (in which case he IS a Christian), or he has not. Jude says nothing about the Christian being in danger of losing his salvation. Nor does James. James is about making sure that one’s faith is saving faith which will result in good works. Jude is admonishing believers to stand firm. Nothing in either place to indicate a loss of salvation. One cannot be regenerated, turned into a new creature, then “unregenerated”.
Salvation is eternal but no verse says one has UNCONDITIONAL eternal salvation. A Christian can fall away, become an apostate therefore no longer has the promise of eternal salvation.
Jude commands the Christian to keep yourselves in the love of God which implies the Christian can fall out of God’s saving, gracious love and become lost. Both Jude and James shows the Christian does have both ability and responsibility to “keep themselves” as to not fall away.
IF eternal security were true, then Charles Stanley would be right in that one could be saved without faith and be saved while not being a disciple of Christ but Stanley’s position is completely against NT teaching