The Nicene Creed, commonly known as a profession of faith, adopted in 325 AD after being written in the city of Nicea. The prayer has been modified since then, but the it has stayed the same at its core; a formula of faith to make it possible for all believers to make a common profession. The fixed form also unites believers and makes it easier to translate into different cultures while keeping the essentials. Common faith is the foundation of religion.
The Creed is originally derived from Matthew 28:19, when Jesus sent forth his Disciples with clear instructions to go and make disciples and baptize them. When someone wishes to be baptized, they were to make a clear and definite profession of faith.
I wrote earlier about five different types of prayer and the value of prayers from the heart and written prayers. The tricky part about pre-written prayers is that they can be hard to make heartfelt if it's something we've been saying over and over. The prayer loses its impact unless we actually think about and understand what we are saying.
The first few lines of what we believe are as follows:
We believe in one God, the Father, the Almighty, Maker of all that is, seen and unseen.
Those first few lines declare several things. Firstly, we are monotheistic; one God. Secondly, God is our Father (and mother), recognizing God as our origin, our authority, and our support (just like a parent). And we take our recognition of this one step further, by declaring our belief in what God has done, creating everything we can and cannot see, having faith in all of it and all God has done.