The Bible is full of descriptions of what is right and what is wrong. For most of the Christian world, it is THE definitive source of such knowledge. So, it should be little wonder that so many Christians spend so much time defining modern ethical questions in terms of right and wrong based on Biblical knowledge. This is generally a good thing. However, it is very easy to get into a position where one sees this information as prescriptive for the world, and to demand that the world conform to this standard. That is not why this knowledge of good and evil was given.
The Hebrew religion of the Old Testament as passed down by Moses was very much a societal religion. They were told how to worship, structure their lives, prepare their food, and punish the sinners. Everything had a process and a purpose, and part of that purpose was to protect the community.
When Jesus came, the religion he taught was not about the collective, but was instead focused on the individual. He taught many of the same principles, but within a completely inverted paradigm. He taught that it is not enough to perform religion, you have to believe it. It is not enough to know the scriptures, you have to understand them. It is not enough to respect others, you have to love them. In these ways and more, He showed that the purpose of religion is to make us better people, not simply to preserve a society.
As Christians, we need to understand this shift. It is a shift from looking outward to looking inward. From compelling obedience to encouraging growth. From enforcing peace, to finding peace. We must first cast the beam from our own eyes, to help a brother with the mote in their eye.
In this light, it should be clear that the definitions of wrong and right as given in the Bible and interpreted under the New and Everlasting Gospel exist for the edification of the individual. They are not meant to be compulsory, and, in fact, would be largely impotent if made so. They are a guide for the believer to find peace and joy in this life and in serving the Lord.
It is quite natural to want to share the path to this surpassing peace and profound joy with those around us, but we cannot lead them down this path if they do not wish to come. To attempt to force the issue often results in a greater resistance to these teachings. We can only effectively share the Gospel through love.
For this reason, there are few guidelines in the new testament for how to treat others except using these two principles: love and forgiveness. Yes, we want them to obey the word of the Lord, but this should be because we love them, not because we want them to be like us. When they sin, we must forgive them, as that is what we all require for our own sins.
Until we are perfect, as only Christ ever was, we must use our knowledge of right and wrong to improve ourselves. And part of that goal for which we strive is learning to love and forgive perfectly.