Revelation 2:9

But thou art rich; spiritually rich, notwithstanding thy deep poverty in temporal things. Here, as in all the epistles, the angel of the church represents the church itself, and what is said to him is said to the church also.

Say they are Jews; a corrupt sect of Judaizers seems to be referred to. They boasted of their Jewish origin, and magnified the institutions of Judaism, but lacked the spirit of true Jews, Romans 2:28-29, and had, instead of it, the spirit of Satan. To true believers, Christ is a faithful, ever-present, all-sufficient friend; making them rich in the deepest poverty, honorable in the greatest abasement, and blessed in the heaviest trials. 2 Corinthians 4:17-18.