As we bear witness about God's moral law, many people have a phobia about being painted as part of the "Religious Right." Along with this fear is a whole host of stereotypes about what standing for godly laws amount to, chief of which has to do with evangelism and reaching out to others with the Gospel.
The main accusation as it concerns evangelism is the idea that we are putting stumbling blocks in front of unbelievers. Instead of hearing about the grace of God, all they see is Christians pouring condemnation upon them. This objection however fails in many ways, especially as it fails to properly understand Law and Gospel. The Gospel makes no sense apart from the holiness of God and the sinfulness of sin. Telling sinners about the Gospel without the necessary work of the Law makes the Gospel superfluous to sinners. If in the process of proclaiming the Gospel, we talk about sin as a general phenomenon, few sinners will actually make the connection to their specific sins. Christianity will be seen as a self-improvement and "spiritual" thing that is good if you want it, but definitely not positing a demand upon all peoples everywhere.
For sinners who love their sins, it makes little difference whether you tell them nicely or you tell them in the midst of heated controversy, for they will reject your message nonetheless. If you tell them nicely, it might be a case of one ear in, another ear out and your message might not be taken seriously. In the midst of controversy, their true hatred of God's law will be manifest as they take the reminders of the moral law seriously. This is not to suggest that we should always seek to be offensive, but it is to suggest that thinking somehow that unbelievers are more likely to respond positively if you refuse controversy is a fool's dream. More importantly, in the midst of controversy might just be the perfect time when they will actually treat what you say seriously, and the relevance of God's law to their lives is made abundantly clear, even if they are to reject it.
Now, it is of course true that stumbling blocks may be placed in front of unbelievers, but only if the Christian witness is done out of spite and hatred, and it is done with merely a statement of the law. Together with the message of what God's Law says must be attached the call of God's grace for salvation. Needless to say, hypocrisy by its proponents is to be rejected, which is to say some measure of holiness is to be expected of believers, for there is nothing more stumbling than an immoral person telling unbelievers immorality is wrong!
As long as it is done correctly, there is no reason why societal witness is antithetical to evangelism properly understood. And unless we would like to deny the commands of God, then we must bear witness in society, not as activists but as believers, seeking not for worldly gain but for God and His Law to be vindicated in our societies.