The different portions of the Ordinary came into the liturgy at different times , with the Kyrie probably being first ( perhaps as early as the 7th century ) .
The Credo being last ( it did not become part of the Roman mass until 1014 ) .
The different portions of the Ordinary came into the liturgy at different times , with the Kyrie probably being first ( perhaps as early as the 7th century ) and the Credo being last ( it did not become part of the Roman mass until 1014 ) .