Why did g-d tell Abraham 4 times in this weeks parsha.

that he will be giving the land of Israel to him and his descendants. ? Also

Do we know

Ultimately the Jews entered into the land with joshua

And later after the Babylonians Chased us out of Israel and then when we came back with the prophet. Ezra.

Was there any difference? To the level of our connection to the land of Israel 

?

And how would that affect our relationship today with the land of Israel?