"Then he showed me a river of the water of life, clear as crystal, coming from the throne of God and of the Lamb, in the middle of its street. On either side of the river was the tree of life, bearing twelve kinds of fruit, yielding its fruit every month; and the leaves of the tree were for the healing of the nations. There will no longer be any curse; and the throne of God and of the Lamb will be in it, and His bond-servants will serve Him;…" Revelation 22:2 (also Genesis 2).
Tree Of Life in Christianity : In addition to the Hebrew Bible verses, the tree of life is symbolically described in the Book of Revelation as having healing properties.
In Catholic Christianity, the Tree of Life represents the immaculate state of humanity free from corruption and Original Sin before the Fall. Pope Benedict XVI has said that "the Cross is the true tree of life."  Saint Bonaventure taught that the medicinal fruit of the Tree of Life is Christ himself. Saint Albert the Great taught that the Eucharist, the Body and Blood of Christ, is the Fruit of the Tree of Life.
In Eastern Christianity the tree of life is the love of God.
In Gift of the Spirit, Stratford Caldecott discusses the fruits:
"The fruits of the tree of life, according to the Book of Revelation, are twelve fold, one for every month of the year. And these are the fruits of the Holy Spirit mentioned by Saint Paul in Galatians 5, because it is the Spirit who joins us to Christ and causes him to live within us..." more here