The symbol of the heavens refers us back to the mystery of the covenant we are living when we pray to our Father. He is in heaven, his dwelling place; the Father's house is our homeland. Sin has exiled us from the land of the covenant, but conversion of heart enables us to return to the Father, to heaven. Jn Christ, then, heaven and earth are reconciled, for the Son alone "descended from heaven" and causes us to ascend there with him, by his Cross, Resurrection, and Ascension.
Source: Catechism of the Catholic Church (Vatican.va)