G4828–συμμαρτυρέω–summartureō

in that they show the work of the law written in their hearts, their conscience testifying with them, and their thoughts among themselves accusing or else excusing them)

συμμαρτυρούσης summarturousēs “are bearing witness”

The Spirit himself testifies with our spirit that we are children of God;

συμμαρτυρεῖ summarturei “bears witness with”

I tell the truth in Christ. I am not lying, my conscience testifying with me in the Holy Spirit,

συμμαρτυρούσης summarturousēs “while is bearing witness”