Allah God of Islam in Chinese / Japanese...

真主 is how Chinese Muslims refer to God (it literally means “True Master”).

Oddly, in China, two different names for God have emerged. Even though Muslims, Christians, and Jews all worship the same God of Abraham.

In Arabic, the word Allah is just the Arabic way to say, God. Arab Christians pray to Allah, just like Arab Muslims. Somehow in China, the title of God diverged.

If you are curious, there are millions of Muslims throughout China but especially in the northwest portion of China known as Xinjiang. Here you will find descendants of Turkmen, Persian, Arab, and other ethnicities. Some are mixed with Han-Chinese blood; others appear to be pure Turkmen. Many have fair complexions, green eyes, and light hair but all are citizens of China. A visit to Xinjiang will shift your paradigm and blow away all of your stereotypes about what it means to be Chinese.

無一是主惟有安拉穆罕默德是安拉的差使 is one of the key creeds of Islam.

While perhaps more often seen in Arabic as

there are many native Chinese Muslims (especially the Hui ethnicity) that do not speak Arabic.

Instead, they use this Chinese phrase to express this idea or statement of faith.

Islam has not taken much of a hold in Japan, so they just use this phonetic version of the Arabic name for God.

I don't recommend アラー for a wall scroll.

Note: Because this title is entirely Japanese Katakana, it should be written by a Japanese calligrapher.