Here's a hypothetical, which I intend to expand upon later with real life examples from the Word. Here it is: What if Adam had passed the righteousness test in the Garden by remaining true to God? If that had happened, there would have been no death in this world or any curse upon it. Adam and all his progeny would live forever. I must wonder in such a scenario how Adam's descendants would have looked upon their Grand Patriarch. Would they be eternally grateful to him for his obedience to God, which would account for their eternal blissfulness, joy and peace upon a pristine earth? Or even more importantly, would they view God's love for them as coming through Adam their federal head, since God loves those who are obedient to Him (Jn 10:17; 15:10), who love Him and his Son (Jn 14:21; 16:27; Ex 20:6; Deut 7:9-11), who keep the demands of his covenant (Ps 25:10; 103:18), who keep his commandments (Ps 103:18), loves those who are just and faithful (Ps 37:28), loves all who call upon Him (Ps 86:5), and loves greatly those who fear Him (Ps 103:11, 17)? After all, if had not been for their patriarch's obedience, where would they be?
I do not think that it's far feteched whatsoever to think that all of Adam's progeny would have been eternally grateful to him for his faithfulness to the Creator. And not only that but that God's love for them comes through their obedient Federal Head. God blessed Adam and all his progeny due to his obedience.