God was not unconcerned with this pagan ignorance, but was patient. As Paul later told the Athenians, "God winked at" it for a time (Acts 17:30). The pagans did have ample evidence, in both creation and conscience, of the true God (Romans 1:20; 2:15), as well as the witness from the Jews in their midst, so they were "without excuse" (Romans 1:20) if they did not acknowledge Him. In fact many had, indeed, already come to "fear God" (Acts 13:16,26) and listen to His Word in the synagogues (Acts 13:42), even though they had been reluctant to become proselytes to the full Jewish religion. It was such as these latter who most readily responded to the gospel of Christ when they finally heard it.

Source:

KJV Defenders Study Bible, by Dr. Henry Morris, Ph.D.
Publisher: Thomas Nelson
Language: English
DEF 10 ISBN 0-529-10444-x
DEF 10-1 ISBN 0-529-10445-8