The New Testament was originally written in Greek although there are older Gnostic Gospels written in Coptic (Egyptian).
The Holy Bible.
Unless individual sects of Christianity have a constitution, I don't know of any Christian constitution. My understanding of a constitution is that it is a blueprint for a political system. The Bible is not a constitutional writing, in my understanding.
Yes they did have a system of writing
A writing system is a system for writing a language or group of languages, for example, the Latin or Cyrillic alphabets.
They had no writing system, but they kept many records of their writing.
there writing system was cuneiform
The Phoenicians developed their writing system from the Sumerian writing system in 1400 BCE, so their writing system came after the Sumerian one.
The Sumerian writing system is called Sumerian cuneiform. The writing was known as the earliest writing system that was traced back in 8,000 BC.
The New Testament is the Christian scriptures.
The Egyptians developed a hieroglyphic writing system.
a writing system
The name of the greek writing system is Cuniform.