We are hypocrites if we say "do as I say not as I do" or if we think (really believe) that we are better or less sinful than another. This cannot be so.
But, as a sinner intent or turning from my sin and seeking Christ, I am well within my Christian duty to let another brother or sister know they are in danger. They are trying to justify and elevate their sin, and no one can do that not me or them.
So many people are quick to say you are judging if you tell another they are in sin. I have had my sins pointed out to me before, and I'm thankful...it's all to easy to fall into sinful ways and feel perfectly good about them. It's not always easy to hear, but ultimately important to hear so that sins can be confessed and forgiven, most importantly recognized.
I do not agree with homosexual marriage. This is not because I am judging those people. My sister-in-law is actively gay and I love her dearly. I have cared for and genuinely liked all of her girlfriends. I enjoy them as people. I do not feel I am less of a sinner or a better person than they...I only feel anxiety. I pray for her soul, I desire her to find the importance of salvation. Sin, all sin, gets in the way of our relationship with Christ. As we embrace sin, the more faded and out of reach that realtionship becomes.
If you really love someone, you want the best for them. We should desire nothing less than heaven for all souls. Correction and information regarding sinful acts is not judgment, but love.
To say "whatever someone else does in the privacy of their home has no bearing on my life blah blah blah..." is shortsighted. What Adam and Eve did has been passed down to thousands of generations. Should we care what they did? Yes. All sin is collective and like a disease that spreads. The more we justify and legalize sin, the more we will suffer as a nation. In other words, personal sin becomes societal sin. Adam and Eve's personal decisions and sin is our problem, and continues to be.
If you see someone doing something wrong, it is not "judging" them to say so. It is information for them, nothing more, nothing less. I would not, nor have not ever said that homosexual sex is wrong and I am perfect. I am so not perfect...but we all need to acknowledge and identify sin in order to help each other find Christ. That is truly loving your neighbor.