GE 17:8 God promises Abraham the land of Canaan as an “everlasting possession.”
GE 25:8, AC 7:2-5, HE 11:13 Abraham died with the promise unfulfilled.

This is only a problem if one refuses to accept the fact of the resurrection and the millennial kingdom of Christ.

Of course, even amillennialists have a response that can address this: they see it as fulfilled in Christ.

All of that being said, it is certain that God has a city prepared for them just as He promised.  Heb 11:16

The promise is certainly enlarged upon so that God’s people have a totally new world in which to live.  Rev 21:1,2 Certainly the skeptic will not fault God for giving more than He initially promised.