It is hard to accept when you discover them, but there are Christians who are dishonest, as Paul encountered,
“And this occurred because of false brethren secretly brought in (who came in by stealth to spy out our liberty which we have in Christ Jesus, that they might bring us into bondage), to whom we did not yield submission even for an hour, that the truth of the gospel might continue with you” (Galatians 2:4-5).
Some Christians in the first century sought association with Paul and his friends, but not to participate truly in his good works, rather to act as spies!
When he discovered who they were and what they were doing, he did not submit to their ways, not even for an hour.
Do not let others ruin what you have in Christ, but stand your ground!