Paul in Romans 7 described his humanity and his captivity to death – described his own condition as being in captivity to “..this body of death”.
And then something happened that released his will and his captive soul – released it into the freedom that it sought. Something had come along and cut off the anchor that held him down, and freed him to explore the liberty he now had from the oppressive laws of sin and of death.
He was free, not only to express that freedom in action, but also in speech – he was free to express how it FELT to be liberated. His feelings suddenly became expressive of who he was, rather than his mind rationalising who he was. His vocalisation expressed his liberty, but also his identity.
The reason for the freedom was to be made plain, not by any derived reasoning of scripture, but simply because he was responding to the one who was the “free-er” of souls and the liberator of lives, Jesus.
[Jesus enables you to perfect your conscience before God][He has perfected our conscience]