Does one sin by writing the name "Abdullah" (عبد اللاه) in an official letter as it is written in official documents, even though the meaning changes, and is this considered an act of disbelief (kufr)? And is it obligatory to request a change of this name in official correspondence?

Scholars have differed regarding the reason for omitting the final alif from the word "Allah" (God). Some say it is to avoid confusion with the word "al-lah" (the active participle of "laha yalhū" - to play or amuse oneself). Others say it is for brevity due to its frequent repetition. Still others say it is a linguistic convention used in writing.

It has also been said that it is so it does not visually resemble "al-Lat" (the idol's name) when paused upon, or due to a dislike of similar-looking letters appearing together in writing.

In summary, the reason for the omission is not agreed upon, nor is it considered a matter of veneration by all. There is nothing in this that necessitates disbelief, especially since writing names with their exact letters is necessary in official documents. The questioner is advised not to succumb to obsessive thoughts, for religion is ease.