How we view "the lost" says a lot about how we view the Gospel. If what Paul said is relevant, we don’t see anyone as a lost cause, we see them as a lost friend. If we really believe God has the power to transform or lives through the Bible, could we really ever dismiss anyone as "too sinful" or "too far gone” for the gospel to have an effect?
Further yet, how we view the lost diagnoses our spiritual maturity. If we cringe (whether visible or not) when "a sinner" shows up at services, it displays we've forgotten the transformative power of the cross in our lives. When we allow our insecurities to prevent us from reaching out to "a sinner" in their time of need, it magnifies the Gospel’s not yet complete transformation in our lives.
We must always remember, Paul was not willing to be beaten, shipwrecked and imprisoned for a powerless Gospel, the gospel he was proud of had the ability to save us, each of us, from our sins. "For I am not ashamed of the gospel, for it is the power of God for salvation to everyone who believes, to the Jew first and also to the Greek." (Romans 1:16)
Let your light shine!