The biggest challenge for the Church as I see it is going to be how Christian individuals express their position against homosexual marriage and homosexual copulation without being perceived as hateful. Yes, there will be people who perceive a Christian hateful just because of the moral stand taken. But others will genuinely want to know why a Christian believes the way he or she does.
The first thing a Christian should try is to have discussions about the issues privately. Voicing disapproval for homosexual marriage at the work place or before several people in a social setting will not be conducive to a discussion that projects genuine love and thus genuine concern.
The second thing a Christian should do is use rehearsed phrases such as "because I care for the souls of people," and "I want people to know the freedom in Christ that I have found," and "I take the position I take because I believe in a heavenly reward and an eternal punishment." Such phrases are not disingenuous because they are rehearsed. Instead they allow for conversation to be set in the parameters of the Christian faith and love for the souls of people.
The third thing a Christian should do is genuinely care for people who are either engaged in homosexual behavior or have embraced the spirit of deception that is found within the homosexual agenda. Actually, the third thing should be the first thing. God's love for the world was first before Jesus was given.