2 Corinthians 11

Paul warned the saints -

"For such are false apostles, deceitful workers, transforming themselves into the apostles of Christ.
14 And no marvel; for Satan himself is transformed into an angel of light.
15 Therefore it is no great thing if his ministers also be transformed as the ministers of righteousness; whose end shall be according to their works."  (2 Corinthians 11:13–15)

Obviously to be safe, on must receive and recognize the Holy Ghost.