Contradiction with Matthew 5:12
Isaiah 9:3 speaks of increasing joy and multiplying the nation, while Matthew 5:12 describes rejoicing and being glad in the face of persecution and difficulty, suggesting joy despite suffering rather than joy from abundance.
Matthew 5:12: Rejoice, and be exceeding glad: for great [is] your reward in heaven: for so persecuted they the prophets which were before you.
Paradox #1
Some people see a translation issue with Isaiah 9:3. In some versions, it says God increased the nation's joy, while others say God did not increase the joy. This difference can confuse people about what the verse really means.