“And God (gave). . . them the Holy Spirit, just as he did to us” (Acts 15:8).
“Now therefore why are you putting God to the test by placing on the neck of the disciples a yoke that neither our ancestors nor we have been able to bear? On the contrary, we believe that we will be saved through the grace of the Lord Jesus, just as they will.” (Acts 15:10-11).
“Certain people.” Short hand for saying people who had an agenda. “Certain people” showed up teaching and insisting that everyone needed to be circumcised. That they needed an outward work of their own in order to effect salvation. A human effort to be saved.
Paul and Barnabas and other new Christians went up to Jerusalem to argue that God does not need our works. They share the good news that God seems oblivious to this bureaucratic requirement and is busy transforming broken hearts and lives (v.3).
Peter is quick to remind everyone about his God going off the rails experience (Acts 10). The Holy and Almighty God gave “those” people the Holy Spirit. THEN! God purified their hearts by giving them faith. Just as they were saved, we now believe and trust that God rescues and redeems us through grace poured out on the cross of Jesus Christ.
There is no test. You are saved through the grace of Jesus Christ. Now run with that!