Fr. Giussani teaches children how to pray through the Psalms and the Gospels. 
“Know that the Lord is God, our maker to whom we belong” (Psalm 100), just as a baby belongs to its mother, so we belong to God. He leads us through life and does not leave us alone, “The Lord is my shepherd; there is nothing I lack” (Psalm 23). 
If someone runs away from God and then feels lost, he can ask Him for help and the Lord welcomes him back and forgives him, “With you is forgiveness” (Psalm 130). But even if we forget Him, He will remember us, “The Lord is faithful forever” (Psalm 116).
There are two prayers after the Psalms that herald the advent of Christ—the Song of Zechariah for the birth of Saint John the Baptist and Mary’s Magnificat after meeting her cousin Elizabeth—these are prayers of thanksgiving because the Lord can do “great things.” 
When Jesus was born, even old Simeon prayed after he recognized the Messiah in that little child, “Now, Master, you may let your servant go in peace, according to your word.” 
Jesus Himself prays to the Father and invites us to acknowledge our sonship. A first move in this direction is to give praise to God and give thanks for the graces we have received. He encourages his disciples to pray even in their time of greatest distress, “Pray that you may not undergo the test”; and in the supreme pain of His killing, Christ Himself relies on the goodness of His Father, “Forgive them, they know not what they do.”
Jesus teaches not only his disciples to pray, but also the Samaritan woman, “You people worship what you do not understand; we worship what we understand”; and He explains to everyone that the heart of the tax collector (“O God, be merciful to me a sinner”) is truer than the heart of the Pharisee, because the first attitude of prayer lies in asking for forgiveness. 
Jesus teaches us that whatever we ask for with faith and perseverance we will get, “Ask, and it will be given to you.” But he also taught us how to pray—through the Our Father. 
From the Letters of Saint Paul and the Acts of the Apostles we are called to take on the same feelings of obedience that Jesus had toward the Father, asking God that Christ be recognized by all people. But all that a Christian witnesses and hopes for is contained in the profession of faith–the Creed as recognition of Christ in our lives.