4 You are receiving not a perishable but a spiritual shield. Henceforth you are planted in the invisible Paradise. Thou receive a new name, which you had not before. Heretofore you were a Catechumen, but now you will be called a Believer. You are transplanted henceforth among the spiritual olive-trees, being grafted from the wild into the good olive-tree, from sins into righteousness, from pollutions into purity. You are made partaker of the Holy Vine. Well then, if you abide in the Vine, you grow as a fruitful branch; but if you abide not, you will be consumed by the fire.
Let us therefore bear fruit worthily. God forbid that in us should be done what befell that barren fig-tree, that Jesus come not even now and curse us for our barrenness. But may all be able to use that other saying, But I am like a fruitful olive-tree in the house of God: I have trusted in the mercy of God for ever —an olive-tree not to be perceived by sense, but by the mind, and full of light. As then it is His part to plant and to water, so it is yours to bear fruit: it is God's to grant grace, but yours to receive and guard it. Despise not the grace because it is freely given, but receive and treasure it devoutly.
Source: Catechetical Lectures (New Advent)