Why Did Catholics and Protestants Add to the Lord’s Prayer?

In my research for an upcoming book, I have revisited my copy of the Holy Bible. This version is a direct translation from the ancient Eastern Aramaic text known as the Peshitta into English, bypassing translations from Hebrew, Greek, and Latin. In Luke 11:2, we discover the Lord's Prayer as taught by Jesus to His Apostles and disciples:

Our Father in heaven, Hallowed be thy name, 

Thy will be done, as in heaven, so on earth. 

Give us bread for our needs every day. 

And forgive us our sins, 

for we have also forgiven all who have offended us, 

And do not let us enter into temptation; but deliver us from errors.

     That is the entirety of the prayer; no additional phrases are necessary. So, why do Catholics and Protestants insist on appending the words, “And deliver us from evil, for the Kingdom, the power, and the glory are all yours. “Now and forever”? In some churches, parishioners even raise their arms during this extraneous sentence. Why?

     First, it’s imperative to recognize that the prayer varies even across the Gospels. While Matthew's version has become the standard for nearly all Christians today, Luke chapter 11 presents a shorter, definitive form that ends with “lead us not into temptation” (v. 4). Thus, it is clear that concluding the prayer at this point is entirely biblically justified.

    Moreover, the appended verse is absent from the “oldest and best” biblical manuscripts. This fact leads most biblical scholars, both Catholic and Protestant, to conclude that it does not belong to the original text. The King James Version, based on the Textus Receptus, relies on less reliable manuscripts compared to those available today. Notably, neither Codex Sinaiticus nor Vaticanus contains this verse. The earliest evidence for the more extended ending of the Our Father appears in a late fourth- or early fifth-century document known as Codex Washingtonensis.

     Catholic translations, such as the Vulgate, the Douay-Rheims, and the New American, have never included this addition, and most Protestant Bibles follow the same standard. Even modern editions of the King James Version acknowledge this discrepancy, including footnotes that note the exclusion of the phrase from older manuscripts.

     The evidence clearly indicates that this phrase was likely a fourth-century addition to the original prayer. A scribe, steeped in the liturgy, incorporated the doxology into Sacred Scripture while transcribing the Our Father passage. This addition then infiltrated later translations of the Bible, eclipsing older texts and becoming commonplace in most manuscripts.