The Bible defines sin, not us. The world does indeed embrace. You asked what it is a Bible believing Christian. It seems as though you don't like the answers.
Hence the reasoning behind the thread.
For me, sin is anything that separates me from God. It's not our place to condemn sin. If you really think the world actively avoids sin, there is nothing I can say to open your eyes. I ask you to provide any scripture where sin, in any form, is tolerated. Please show any scripture where sin is defended. We are not called to be tolerant, we are called to be loving. Somehow it seems you've adopted the nonbelievers idea of what Christianity should be in exchange for what the Bible says a Christian should be.
1 Corinthians 2:14 (NLT)
But people who aren’t spiritual
can’t receive these truths from God’s Spirit. It all sounds foolish to them and they can’t understand it, for only those who are spiritual can understand what the Spirit means.