It is often said that Jesus somehow changed mankind's relationship with God, at least in potential if not fact. It is taught that the sin of Adam severed the relationship between God and man and then Jesus established a basis for a renewed relationship with the divine.
All of the above begs the question of where in the Bible the idea of a severed relationship derives. Then what defines a relationship in the base case.
The idea of broken relationship probably comes from a verse like Isaiah 59:2 that says your iniquities have separated you from your God. Why does that have to mean that God rejects us because of our sin instead of meaning that our thoughts and behaviors simply blind us to God's presence and truth? I know the same verse in the KJV says He will not hear because of sin, but the word translated "will not hear" can also mean "will not be heard". That provides a dramatically different twist, one which corresponds much better with the preceding verse in the same chapter. Also, it is worth noting that the author says that God is your God despite your iniquities.
Then we have the Genesis account of Adam and Eve being driven from the Garden. It is perhaps easy to conclude that God was upset and rejected any further relationship with humanity at that time.
But despite the story of the Fall, what the Bible portrays after that event is God's undeterred work on and through humanity. He spoke to man, directed man, and maintained a collective relationship, at least with Israel. God's actions, as recorded in the Bible, don't reflect remoteness, indifference, or neglect on God's part. It is a strange description of a severed relationship.
I question quite strongly whether the assumption of a lost relationship is biblically valid. The relationship may have changed in some sense, probably more in man's mind than God's, but it was far from over. God' purpose is unreservedly developed throughout subsequent human history without regard to man's compliance or contributory involvement.
Wikipedia says that An interpersonal relationship is a strong, deep, or close association or acquaintance between two or more people that may range in duration from brief to enduring. This association may be based on love, common interests, regular business interactions, or some other type of social commitment.
One might suggest that relationship involves interaction, communication, a certain level of commitment to those in the relationship, and some sense of unity. Out of that description I ask whether a relationship can exist and one or more of the parties be unaware of it. Unity in some sense and interaction can more easily be envisioned as existing unknowingly, but communication and commitment, not so much. However, when we speak of the divine relationship, some may be able to perceive of God speaking without the human hearer being fully aware of the source. Likewise, we might consider whether a commitment on God's part is not enough to seal the God-mankind relationship even without man's corresponding commitment or acknowledgement.