The Catechism in Questions & Answers

718. What instructions did Jesus give concerning prayer?

In the Sermon on the Mount, Jesus gave important instructions concerning prayer (cf. Matthew 6: 5-8). We are not to make an outward show of prayer nor are we to use a lot of words. We may address God as “Father”. Prayers should come from the heart.
In view of His return Jesus admonished: “Watch therefore, and pray always that you may be counted worthy to escape all these things that will come to pass, and to stand before the Son of Man” (Luke 21: 36).