Tomorrow, Aug 23rd, is the second Sunday after Ascension of St. Mary. Gospel reading for tomorrow is St. Luke Chapter 11 verses 9 - 20. This is the very chapter wherein the disciples ask Jesus to teach them how to pray, and the Lord's Prayer (Our Father...) is narrated. However, we tend to use the Lord's prayer that is narrated in St. Matthew Chapter 6, which is bit more elaborate.
St. Luke Chapter 11 verses 9 - 20
9 "So I say to you: Ask and it will be given to you; seek and you will find; knock and the door will be opened to you.
10 For everyone who asks receives; he who seeks finds; and to him who knocks, the door will be opened.
11 "Which of you fathers, if your son asks for[a] a fish, will give him a snake instead?
12 Or if he asks for an egg, will give him a scorpion?
13 If you then, though you are evil, know how to give good gifts to your children, how much more will your Father in heaven give the Holy Spirit to those who ask him!"
14 Jesus was driving out a demon that was mute. When the demon left, the man who had been mute spoke, and the crowd was amazed.
15 But some of them said, "By Beelzebub, the prince of demons, he is driving out demons."
16 Others tested him by asking for a sign from heaven.
17 Jesus knew their thoughts and said to them: "Any kingdom divided against itself will be ruined, and a house divided against itself will fall.
18 If Satan is divided against himself, how can his kingdom stand? I say this because you claim that I drive out demons by Beelzebub.
19 Now if I drive out demons by Beelzebub, by whom do your followers drive them out? So then, they will be your judges.
20 But if I drive out demons by the finger of God, then the kingdom of God has come to you.
The earlier part ( verses 9 - 13) talks talking about perseverance in Prayer. There, Jesus tells us that if one of us need 3 loaves of bread and go to a friend in the middle of the night, he may not give us when we ask him at first. However, if we keep on asking, asking, asking, and asking he will give us whatever we asked for, due to our persistence. Similarly, we need to keep asking, asking, asking and asking to God - and He will answer our prayers.
Verses 14 onwards talks about Jesus and Beelzebub.
Source: The Holy Bible (New International Version)