In the first Pasuk of this week’s Parsha, Hashem tells Avram, לך לך מארצך. Rashi comments, להנאתך ולטובתך, Hashem is telling Avram to go for his own benefit; if he complies, he will be greatly blessed, but if he chooses not to go, he will not be blessed. If Avram goes for his own benefit, why is this considered one of the ten ניסיונות (tests) with which Hashem tested Avram?
Rav Moshe Feinstein, in Darash Moshe, deals with this question. He answers that the real test was not whether Avram would go; rather, it was whether he would have second thoughts. It is very hard to act upon a command whose logic cannot be seen. Avram could have easily asked why Hashem could not just grant him the blessing in his current location without him having to go through the trouble of moving. However, Avram went without ever having second thoughts, thereby showing his true faith in Hashem.
This same concept presents itself again to Avraham when Hashem promises Avraham that Yitzchak will become a great nation and then contradicts Himself by commanding Avraham to slaughter Yitzchak. Even though this too, seemed illogical, Avraham wholeheartedly brought Yitzchak to be slaughtered, without any second thoughts. This again shows Avram’s complete faith in Hashem, which is why he was chosen as the father of Klal Yisrael.