We will not because we cannot. Unlike those who embrace liberal theology, we do not see Christianity as a system of beliefs that we can just change as we see fit. We do not see the Bible as a mere collection of ancient religious writings that can be disregarded or reinterpreted to mean something other than what it says.

Why not just join the revolution? This question seems obvious to many people who look at conservative Christians and honestly wonder why we cannot just change our views on homosexuality, same-sex marriage and the entire LGBT constellation of issues.

We are constantly told that we must abandon the clear teachings of the Bible in order to get “on the right side of history.”

It’s not that we don’t understand the argument – we just cannot accept it.

Clearly, many more liberal churches and denominations are not only accepting that argument, they are running away with it. Each of these churches once defined marriage exclusively as the union of a man and a woman, and every one of them once defined human sexuality and gender in agreement with the Bible and with historic Christian teachings.

Now, at least some people seem genuinely perplexed that conservative Christians will not just go along with the program to redefine Christian morality, marriage, and doctrine.

We will not because we cannot. Unlike those who embrace liberal theology, we do not see Christianity as a system of beliefs that we can just change as we see fit. We do not see the Bible as a mere collection of ancient religious writings that can be disregarded or reinterpreted to mean something other than what it says.

Instead, we understand the Bible to be what it claims to be, nothing less than the inspired and inerrant Word of God. We understand Christianity to be grounded in specific truths as revealed by Christ and the Apostles and given to us in the Holy Scriptures. We believe that Christianity is defined by what the Bible calls “the faith once for all delivered to the saints.”

These days, we find ourselves opposed, dismissed and ridiculed for holding to truths that the Christian church has taught for 2,000 years.

The reality is that Christians who define Christianity in terms of historic Christian doctrine and moral teachings do not believe merely that these teachings are true, but that they point to the only way that will produce real and lasting human happiness. We are not merely opposed to same-sex marriage because we believe it to be contrary to Scripture; we believe that anything opposed to Scripture cannot lead to human flourishing.

There can be no question that we are living in the midst of a vast revolution in moral values. We see it, sense it and do not deny it. The more liberal churches and denominations can simply accommodate themselves to this moral revolution and move on. But in so doing they are abandoning, not only the clear teachings of the Bible but also the essence of the Gospel of Jesus Christ.

That Good News promises salvation to anyone who believes in Christ as the crucified and resurrected Lord and who repents of sin. If we misunderstand or misrepresent what sin is, we undercut the work of Christ and our knowledge of the fact that we need a Savior. Furthermore, if we abandon the teachings of the Bible on sexual morality, we confuse the world – and ourselves – about repentance.

The Bible is not merely an inspired book of doctrinal truths. It tells a story of God’s act of creation and of the reality of human sin, of the depth of God’s saving love for us in Christ, and the story of where history is headed. The Bible also warns us against any effort to change that story or to tell it wrongly. Yes, it warns us against the sin of teaching what the Bible calls “another gospel” than the gospel of Jesus Christ.

The current American landscape includes more liberal churches that are doing their best to join the sexual revolution and conservative churches that cannot follow. Simple honesty requires acknowledgment that it is the conservative churches that are teaching what Christianity has taught for two millennia.

We are told that holding to biblical authority and the historic Christian faith will lead to our marginalization.

Perhaps so, but it is the more liberal churches that have been hemorrhaging members by the millions for the last four decades and, even in a secularizing age, it is the most secularized denominations that have suffered the greatest membership losses.

We do understand what is at stake in terms of the human judgment of history, but we are far more concerned about the divine verdict of eternity. We must speak the truth in love and seek to be good neighbors to all, but we cannot abandon the faith just because we are told that we are now on the wrong side of history.

This article first appeared in The Courier-Journal, online on Nov. 4, 2015, and in print on Nov. 5, 2015. Dr. R. Albert Mohler Jr. serves as president of The Southern Baptist Theological Seminary. This article is taken from his blog, and is used with permission.