Abraham was called by God to go out into a place which he was promised would later be his inheritance. Abraham obeyed, not knowing where he was to go. He lived in the land of promise (as did his son, Isaac, and later his grandson, Jacob - both heirs with him of the same promise) only in tents, like mere visitors. During their lifetimes they did not actually receive the land as theirs that they were promised. It is written that they died in faith, however - persuaded of the certainty that they would receive from God all that He had promised.
We learn from the writer of the book of Hebrews that there was something else going on at another level in the lives of these three men (called "the patriarchs" because God 's promise included that their descendants would be a great nation, a nation with a unique calling). Yes, an actual, specific, geographical portion of land on earth would indeed be theirs - as servants of God with a special and holy assignment. But they were simultaneously looking for "another country." At the same time that they were convinced of a promised earthly possession, in their spirits they "saw afar off" a heavenly country that they desired.
This vision was not for these patriarchs alone. There have been countless others who lived before us (a "great cloud of witnesses") who caught a glimpse, too, of that "better country." All of these people walked their lifetimes on earth as pilgrims, as sojourners just passing through, as it were. They all agreed and acknowledged that this earth was not their true home. They had a homeland, and in the deepest recesses of their beings, they longed for it.
It is written that Abraham was looking for a city of strong foundations whose architect and builder was God Himself. (Hebrews 11:10) It was different from any city built by man, and somehow Abraham (and others of like faith in God) was able to perceive it in the distance, and his inner man welcomed and embraced it. Just as he could have gone back to the wealthy, earthly land of Ur that he had left, he could have gone back to "the good things" that this world offered; but he didn't want to. In their spirits, all these people had a different perspective. They were living for heaven, for the things of God. And because that was what they were looking for, and longing for, God was not ashamed to be called their God. For He had indeed prepared a heavenly city for them.
Perhaps the innate recognition of it as our homeland is present somewhere in the hidden depths of our consciousness, because it is our true fatherland. Perhaps, in a sense, we were once there. Maybe we do not quite wholly feel at rest and at home on this earth, because our real home is in the very heart of God, our Father - and always has been.