It is a long standing tradition to use the Lord's prayer as a sample text for illustrating natural languages, for instance, the mid-16th century Cosmographia by Sebastian Münster contains the Lord's prayer in Finnish as an illustration of the Finnish language.
It has the advantage of being available in many languages, including otherwise ill-documented or dead languages.
Its disadvantages are the religious bias and the fact, that some very marked constructions tend to occur in this text (in German, there is a relative clause in the second person singular ..., der Du bist im Himmel, ... a really rare beast).
In addidition, the Greek source contains a word whose meaning is not securely known, namely the word ἐπιούσιος (epiousios), for more information see this answer on linguistics.se.