Prayer: Our Father who art in Heaven

As a Catholic, I heard the prayer “Our Father” frequently. However, there are many variations of the prayer Our Father. The most common one is the modern translation, “Our Father in Heaven, holy be Your name…”

Don’t know why, different area different style. I heard a weird version of “Our Father”, that is: “Our Father who art in Heaven, holy be Your name…”

Why I say it is weird? Have you read the words like: Thee, Thy, Thou, Thine and else? These are the archaic English, which means “You”.
thee = you
thou = you
thy = your
thine = yours
(Hope that I do not make it wrong…)
Check this: http://dan.tobias.name/frivolity/archaic-grammar.html

Then, the verb “are” for the archaic English for the Second Sinular Person will be “art”. However, if the prayer said as “Our Father who art in Heaven, holy be Your name…”, then what does it mean?

From what I know, the correct version is “Our Father who art in Heaven, holy be Thy name…”, if like this, then everything will be reasonable.

Why I focus on this? May be I am the only person who is stupid enough to think that, “Our Father who art in Heaven” means: Our Father who “artistically design the world in Heaven”, when was young.