Here it is important to understand the nature of faith. Faith (Hebrews 11:1) means that you trust God to fulfill his promises. Abraham saw how God fulfilled some promises (his offspring), but other promises (the promised land) were not fulfilled yet. Faith (Hebrews 11:1) is also the assurance of that which is hoped for although you do not see it (yet).
13 These all died in faith, not having received the things promised, but having seen them and greeted them from afar, and having acknowledged that they were strangers and exiles on the earth.