Praying to Our Loving God
One of the most important titles for God in Christianity is "Father." This title played an important role in the formation of the theology of the Trinity as well as being the anchor for the Our Father (Pater Noster) or Lord's Prayer, the most important Christian prayer given by Jesus.
Jesus did not merely use the title "Father" for God. He used the Aramaic word "Abba," which is a term of endearment for God with a literal meaning of “Daddy.” Thus, when Jesus used the word "Abba," He was expressing His unique, intimate relationship as the Son to God the Father. It is a powerful reminder that our access to the Father comes only through Jesus.
Yet Jesus teaches us to call the Father "Abba" too. This is because through Jesus we too have unique, intimate access to the Father. We share in Jesus' relationship with the Father so intimately that we can call the Father "Abba" and become adopted brothers and sisters of Jesus.
Calling God "Abba" or "Father" was a unique contribution of Jesus to the Judeo-Christian tradition. Before Jesus, we have no clear record of public prayer referring to God as "Father." It would probably have been scandalous to refer to God as "Abba," because it implied a level of intimacy that ancient Jews were uncomfortable with.
However, Jesus, through His sacrifice on the cross, allows us, as fellow children of God, to speak to God on personal terms, even to the point of crying "Abba, Father" in prayer.