When I was young, one of the many lessons my parents taught me is that when someone is doing something wrong - when they are sinning - they will, without a doubt, try to get you to join them in their sin. It makes them feel better about what they are doing. It allows them to not feel alone in their error. They can even then pretend there is nothing wrong with what they are doing if "everyone is doing it".
It is one of the most important lessons my folks ever taught me. In that knowledge of why people want you to join them in their wrong doing, a determination to not be influenced by their pressure can begin to be built in a young, developing mind. When one determines to stand against evil, evil flees.
That leads me to another important lesson my folks taught me. When one is saved and sticks to one's convictions, there is no need to worry about hurting the feelings of friends that are not saved, by removing ones self from their company - because they will most likely leave you, first. They will not be able to handle the light of God's love that now shines in you, until they are ready to come to that light for themselves.
Those that are walking in darkness do not want to be exposed to God's light, because they have within their conscience an ability to understand that what they are doing is wrong. And that can be painful. They are afraid of the light, because it makes their darkness that much more stark in contrast.
It is frightening to be alone in sin. Those living in the darkness without the benefit of understanding God's grace may put on a brave front, they may exude a cocky attitude of self assurance; as well as a disdain for those that stand for what is right; but in reality, they are fearfully floundering and are in desperate need of our prayers.
Those of us that live in the light of God's love have a responsibility to stand stronger when tempted by those in darkness. We must shine brighter to show those who would tempt us, or mock us, that there is a much better way.