they become awsome people that's how
The Abbasids used calligraphy in books
they would decorate there whole village.
Much decoration in Muslim temples involves calligraphy.
Calligraphy is the art of writing. The Muslims use it in writing the text of the holy Qur'an. They also use it while writing verses on walls of mosques for decoration.
Muslims have a varied perspective on art. While some branches within Islam have historically discouraged or imposed limits on representational art, many Muslims have embraced and contributed to a rich tradition of art, including calligraphy, geometric designs, and architectural ornamentation. The Islamic artistic tradition values spirituality, beauty, and the use of art to convey religious teachings and inspire piety. However, individual beliefs and interpretations can differ among Muslims, leading to a range of attitudes towards art.
Classic Muslim art often uses geometric shapes.
Islam forbids drawing animals or people. So for decoration, Muslims use geometric patterns, or tessellations.
Arabic calligraphy .
Much Islamic art is geometric, due to sanctions against the depiction of living things (which might be worshipped instead of Allah).
Much decoration in Muslim temples involves calligraphy.
Islam prohibits the use of the pictures of living beings. So, the Muslim artists use geometrical and vegecal patterns.
The use of geometric shapes in painting is used in abstract art. Abstraction indicates a departure from reality in depiction of imagery in art.
Geometric abstraction is a form of abstract art based on the use of geometric forms sometimes, though not always, placed in non-illusionistic space and combined into non-objective compositions.
I think because it's a very beautiful calligraphy with many styles of writing giving it a great flexibility that has enabled people to use it in the ornaments, decorations & artistic works. Since Muslims don't believe in representing Allah (God) or prophets or even Muhammad's companions with images,it has been widely using in the Mosques to write Allah's name along with verses from the holy Quran or the prophet's sayings or even wisdom. With the passage of time its usage was expanded & developed until it became an independent & important art in the Islamic cultural heritage.