In Matthew 11, it reads
When John heard in prison what Christ was doing, he sent his disciples to ask him, "Are you the one who was to come, or should we expect someone else?" (Matthew 11:2-3)
It seems that John did not know who Jesus is. However,
1. John's mother and Jesus' mother were relatives.
2. John was the one who baptized Jesus.
Then Jesus came from Galilee to the Jordan to be baptized by John. But John tried to deter him, saying, "I need to be baptized by you, and do you come to me?" (Matthew 3:13-14)
How should we interpret the seemingly contradicting passages?