Before he dies Moses warns the people (31.18) that if they betray their heritage, God will turn away from them and ‘ I will hide my face.’ “Haster Astir Pani Mayhem.” The same phrase is used again in the Ha’azinu “Astir panai mayhem.”
This is how many rabbis have explained the suffering we experienced in exile. Why God did not prevent the Holocaust. Hester Panim became a core concept. Not that God disappears. That would not make any sense theologically. But that the means of communication have become blocked. We ourselves can so alienate ourselves from God that we cannot find our way back.
But even this is a problem. If we believe in repentance, teshuvah, then anyone ought to be able to return to God at any time. It is not the theoretical possibility that is being called into question. Rather it is the practical. The more we lose contact, the more alienated we feel and the more difficult it is to return. In other words, we have driven God out of our lives.
This concept can also be understood on a national level. Regardless of what individuals do, we can create a historical sequence that it is very hard to reverse or come back from. This explains 2,000 years of exile. And yet, as the Torah promises, no matter what, we can come back, however long it may take. God’s time is different to ours.