Why we are able to run back to him is the essence of his love and sacrifice. The flesh (man) after the fall and having his eyes open (mind and spirit) to corruption and disobedience no longer had perfect communion with God. We died a spiritual death. The some knowing fallen angel (serpent) that had a glimpse of things to come told a half truth in saying that man would not surely die. He was right to the extent that death was not assured in the physical ( not recognized) sense and it was not instant, yet we did die.
The body we had prior to the fall could live for ever. We did not have skin as we know it until after we sinned and was punished by being made to leave the Garden and his continuous presence. Running back to him (God) is best appreciated when we understand the plan of salvation that was instituted for man to be redeemed after his free will action (act of disobedience).
God made a way (provision ) for man to return to the love that was shared in the Garden even after man betrayed him and adjoined himself to the spirit of the fallen angels. What manner of love is this? The creation turns against the Creator and yet the Creator, creates a way through love and sacrifice (of himself) for him to return to the place in relationship that man had with him before the fall.
Knowing this is to comprehend the envy and jealousy (hate) that fallen angels (demons) have of man. They can never return to their original communion with God after their disobedience and revolt. We can not only return to our original place but as we continue to wrestle with life on earth and battle unclean spirits (thoughts) and find ourselves feeling distant from our connection we can run back (repent) pray and feel a sense of renewal in our walk (relationship). This is a function of the "Soul" that was given to man.