What does John 10:42 mean?

Jesus has temporarily left the area immediately around Jerusalem, due to rising threats from the local religious leaders (John 10:39–40). He has gone to Perea, where John the Baptist preached prior to Jesus' public ministry (John 1:19–29). That preaching seems to have made the people much more receptive to Jesus' teachings. Those who have heard John's message recognize Jesus because of His miracles and the fact that He fits the predictions given them by John (John 10:41). This is like the way the Samaritan woman's testimony opened interest within the town of Sychar (John 4:39). This, again, prepared that area for the apostles after Jesus' ascension (Acts 8:4–8).

Jesus' avoidance of danger is only temporary. Soon after this, He will return to Judea, much to the fear of His disciples (John 11:6–8). He will then re-enter Jerusalem for the last time before being arrested and executed on the cross.