Jesus "was praying at a certain place, and when he ceased, one of his disciples said to him, 'Lord, teach us to pray, as John taught his disciples.'"(Lk 11:1) In response to this request the Lord entrusts to his disciples and to his Church the fundamental Christian prayer. St. Luke presents a brief text of five petitions(Cf. Lk 11:2-4), while St. Matthew gives a more developed version of seven petitions. The liturgical tradition of the Church has retained St. Matthew's text (Cf. Mt 6:9-13).
"Run through all the words of the holy prayers [in Scripture], and I do not think that you will find anything in them that is not contained and included in the Lord's Prayer" - St. Augustine, Ep. 130,12,22:PL 33,503.
It is therefore evident the Lord's Prayer is the most important prayer in Christianity as its content wholy summarizes the message delivered by the Four Gospels: putting God's will first while personal desires last in additional to praying for mercy from our Lord. As the The Most Reverend Savio Hon Tai-fai (Secretary of the Congregation for the Evangelization of Peoples, Vatican) rightly noted, "Such is the gist of the Gospels: The mortal ones have their own will and desires, while God has God's own will and desires; if one choses to follow God's desires, then one shall effortlessly fulfill all of one's desires (這是福音: 人有人意，天有天意，順得天意，自能如意)" (2)."The Lord's Prayer is the most perfect of prayers. . . . In it we ask, not only for all the things we can rightly desire, but also in the sequence that they should be desired. This prayer not only teaches us to ask for things, but also in what order we should desire them." - St. Thomas Aquinas, STh II-II,83,9.