To remain in God and God in us is really a reflection of the love affair God wants with us. In the Old Testament the prophets revealed that there was a spousal relationship between God and his Chosen People. Even so, His people were unfaithful many times in their covenant relationship with God. Through Hosea God revealed that he would chastise and purify the people. Then he would espouse them to himself once more. Just as spouses can live together but be separated from each other, so too we can have the same relationship with God.  On the other hand, just as two spouses can live their sacramental covenant in intimate union with each, growing in their love for one another, so too we can have this intimate relationship with God. This union is a mystery that is attainable by grace.

That is why Jesus revealed the process in relationship. Encounter, walking with him as a disciple, embracing his word in faith because of who Jesus is, accepting and falling in love with God, growing in this love by doing his will because it is the will of the beloved.