What roles does a Christian play in society?

A christian besides advocating with his mouth should set a good example
By obeying the law, useing non abusive language, dressing modestly according to proper gender, becoming married to produce offspring,
Abstain from illegal drugs, and legal drugs that harm the body.
A christian should demonstrate human compassion and speak the truth.

Above all a christian should do his best to personally obey Jesus Christ's example for true worship to god.