See then that ye walk circumspectly
Eph 5:15 (KJV)
There is no such thing as negative influence. We are all positive in the
place we occupy, making the world better or making it worse. –T. DeWitt Talmage
When a Christian tells a sinner of their sin and the redemption that can be found in Christ alone, they are a positive influence. Positive influence is not merely being holly and jolly and "optimistic." --Ryan Marks