Here are some words from the Puritans in 1647:
Saints by profession, are bound to maintain an holy fellowship and communion in the worship of God, and in performing such other spiritual services as tend to their mutual edification; as also in relieving each other in outward things, according to their several abilities and necessities. Which communion, as God offereth opportunity, is to be extended unto all those who, in every place, call upon the name of the Lord Jesus (Westminster Confession of Faith, 26.2).
How does God want us to pray so that He will listen to us?
First, we must pray from the heart to no other than the one true God, who has revealed Himself in His Word, asking for everything He has commanded us to ask for.
Second, we must acknowledge our need and misery, hiding nothing, and humble ourselves in His 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 He promised us in His Word (The Heidelberg Catechism #117).
Why do Christians need to pray?
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 Him for them (The Heidelberg Catechism, #116).