The Lord's Prayer: †Protestants †say "for Thine is the Kingdom and the Power and the Glory forever" but Catholics do not. †Why? †Which is correct? †Thanks much.
"In this manner, therefore, pray: 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 forgive our debtors. And do not lead us into temptation, But deliver us from the evil one. For Yours is the kingdom and the power and the glory forever. Amen" (Matthew 6:9-13).
"Now it came to pass, as He was praying in a certain place, when He ceased, that one of His disciples said to Him, "Lord, teach us to pray, as John also taught his disciples." So He said to them, "When you pray, say: Our Father in heaven, Hallowed be Your name. Your kingdom come. Your will be done On earth as it is in heaven. Give us day by day our daily bread. And forgive us our sins, For we also forgive everyone who is indebted to us. And do not lead us into temptation, But deliver us from the evil one" (Luke 11:1-4).
What is commonly referred to as the Lord's Prayer was a sample prayer to teach the disciples how to pray. It was not intended to be repeated word-for-word -- that is what "in this manner" means. To recite this prayer word-for-word would contradict what Jesus said earlier in Matthew 6 about not praying hypocritically. To say something by rote is to ask without meaning.
There is a disagreement over the last part of Matthew 6:13. Generally the Byzantine texts (which most ancient texts of the Bible are in this family) have the last part. Many of the old manuscripts not in this family do not have the last line. So the difference really depends on which set of manuscripts is thought to be more accurate.