Heidelberg Catechism - Lord's Day 45

116. Q . Why do Christians need to pray?
       A. Because prayer is the most important part of the thankfulness God requires of us. And also because God gives his grace and Holy Spirit only to those who pray continually and groan inwardly, asking God for these gifts and thanking God for them.

117. Q . What is the kind of prayer that pleases God and that he listens to?
       A. First, we must pray from the heart to no other than the one true God, revealed to us in his Word, asking for everything God has commanded us to ask for.
Second, we must fully recognize our need and misery, so that we humble ourselves in God’s majestic presence.
Third, we must rest on this unshakable foundation: even though we do not deserve it, God will surely listen to our prayer because of Christ our Lord.
That is what God promised us in his Word.

118. Q . What did God command us to pray for?
       A. Everything we need, spiritually and physically, as embraced in the prayer Christ our Lord himself taught us.

119. Q . What is this prayer?
       A. Our Father in heaven, hallowed be your name.
Your kingdom come.
Your will be done, on earth as it is in heaven.
Give us this day our daily bread.
And forgive us our debts,
as we also have forgiven our debtors.
And do not bring us to the time of trial,
but rescue us from the evil one.
For the kingdom and the power and the glory are yours forever.
Amen.