Genesis 1-4

In the Garden
The Lord God walked in the garden. What a beautiful picture of what life lived in communion with God was--and is supposed to be! One of the effects of the Fall into sin (Genesis 3 and following... and following...), is not only the casting out from the Garden but this break in communion with God.

But God refuses to give up on his creation. God restores the communion broken with him by allowing Jesus Christ, God the Son, to be broken on the Cross, and thus literally reestablishes communion through brokenness. We confess this every time we break the break of the Holy Communion: our brokenness is only restored through Christ's willing "breaking open" for us (cf. John 19:34).

Tree of Life
The Tree of the Knowledge of Good and Evil gets all the good press in the creation narrative, probably because it is by eating of this tree that humankind commits the first act of disobedience to God, thus breaking communion with him. But we might miss the Tree of Life.

Christian interpreters have long seen the fulfillment of the Tree of Life in Genesis in the Tree of the Cross in the Gospels. The Proper Preface (beginning of the Communion prayer) for Palm Sunday reads: It is indeed right and salutary that we should at all times and in all places offer thanks and praise to you, O Lord, Holy Father, through Christ our Lord; who on the tree of the cross gave salvation to all, that where death began, there life might be restored, and that he who by a tree once overcame, might by a tree be overcome.

It's that last part that always gets me... and is potentially confusing. Here is the explanation: that he who by a tree once overcame [satan by the Tree of Knowledge of Good and Evil], might by a tree be overcome [Christ's victory on the Tree of the Cross, the Tree of Life].

This Tree of Life is picked up in the Book of Revelation as well (22:1-2, also 22:14). This Tree--in Eden, on Golgotha, in the New Jerusalem--is central to the new Communion with God after our original communion with him was severed.