Avraham had thought about and searched relentlessly for God while living outside of Israel. However, his first revelation from God was a command to move to Israel. This may be an illustration of what Chazal teach us regarding our relationship to God and Eretz Yisrael. The Gemara ()כתובות קי: teaches כל הגר בארץ ישראל יש לו אלוק וכל הגר בחוצה לארץ דומה כמי שאין לו אלוק - One who lives in Israel has a God and one who lives outside of Israel is as if he has no God.
One can have a full relationship with Hashem only if he lives in Eretz Yisrael. This appears to be the lesson with Avraham. Only when he will go to Israel will his quest for closeness to Hashem be realized fully.