D. C. Barnes wrote a three part article on “regeneration” in the 1944 Evangel. part one: The Rationality of the New Birth” part two: The Agents of the New Birth and part three: The Water of the New Birth, conversation with Nicodemus.
I will link them up in the comment section.
http://pentecostalarchives.org/digitalPublications/USA/Church%20of%20God%20(Cleveland%20TN)/Church%20of%20God%20Evangel/Unregistered/1944/Dixon/1944_06_17.pdf
http://pentecostalarchives.org/digitalPublications/USA/Church%20of%20God%20(Cleveland%20TN)/Church%20of%20God%20Evangel/Unregistered/1944/Dixon/1944_07_15.pdf
http://pentecostalarchives.org/digitalPublications/USA/Church%20of%20God%20(Cleveland%20TN)/Church%20of%20God%20Evangel/Unregistered/1944/Dixon/1944_07_22.pdf
These articles must have laid the groundwork for the Declaration of faith.