What The Bible Says …

Genesis 12
 
Now the Lord had said to Abram (changed to Abraham Genesis 17)
“Get out of your country,
From your family
And from your father’s house,
To a land that I will show you.
I will make you a great nation;
I will bless you
And make your name great;
And you shall be a blessing.
I will bless those who bless you,
And I will curse him who curses you;
And in you all the families of the earth shall be blessed.” 
Genesis 15 records that the land grant was/will be much larger than Israel currently has:
“To your descendants I have given this land, from the river of Egypt to the great river, the River Euphrates— 19 the Kenites, the Kenezzites, the Kadmonites, 20 the Hittites, the Perizzites, the Rephaim, 21 the Amorites, the Canaanites, the Girgashites, and the Jebusisites”
Genesis 17
When Abram was ninety-nine years old, the Lord appeared to Abram and said to him, “I am Almighty God; walk before Me and be blameless. And I will make My covenant between Me and you, and will multiply you exceedingly.” Then Abram fell on his face, and God talked with him, saying: “As for Me, behold, My covenant is with you, and you shall be a father of many nations. No longer shall your name be called Abram, but your name shall be Abraham; for I have made you a father of many nations. I will make you exceedingly fruitful; and I will make nations of you, and kings shall come from you. And I will establish My covenant between Me and you and your descendants after you in their generations, for an everlasting covenant, to be God to you and your descendants after you. Also I give to you and your descendants after you the land in which you are a stranger, all the land of Canaan, as an everlasting possession; and I will be their God.”
 
If you read these passages together with the historical facts, you have the basis for almost five years of research, two books and almost 10,000 blog posts.
 
It would be nice for me to tell you that this issue of the rightful ownership of the land will all work out in the end between Israel and her neighbors, but there are three wars prophesied to take place that will settle the issue.