First, you may be saying, “I’ve been a Christian for years and have never heard of this doctrine.” Most likely you have and just didn’t realize it. Substitutionary atonement refers to the doctrine that Jesus died in place of others to work the forgiveness of sins through his blood. In other words, Jesus died to forgive your sins and save you the penalty of everlasting death and separation from God.
Now you may be saying, “Of course I believe this doctrine, all Christians do!” Actually, this is a wonton miscategorization. There exists an ever-growing branch of Christian scholarship that finds this doctrine to be a later interpretation of the death of Jesus. According to this branch of Christianity, made up of liberal Christians including many Anglicans, of note the retired Bishop John Shelby Spong, Jesus’ life was originally the focus of his followers, and it is to this life-view we should return. Spong has been known to go as far as labeling the doctrine “Divine child abuse.” Others, while not making such strong remarks, feel the doctrine to stand at odds with the God of love.
However, many conservative Christians decry this “secularizing” of the Gospel message as misguided at best and dangerous at worst. Rejecting the doctrine of substitutionary atonement is tantamount to rejecting what they see as the message of Christ. To many in this group, liberal Christians aren’t Christians at all. Popular Christian writers from Lee Strobel to Rick Warren base their entire ministries on the doctrine of substitutionary atonement.
In response, the liberal Christians point out that the “biblical literalists” actually reject much of the Bible, including strict Hebrew dietary restrictions, head coverings and silence for women, and numerous other minor laws. In addition to these, liberal Christians assert that taking the Bible literally would justify everything from slavery to child abuse.
You may now be shaking your head in confusion, wondering what a devout Christian should believe. My response will echo Christian reformists such as Spong by saying that it is not one’s adherence to doctrine that makes a Christian, rather one’s dedication to the life and teachings of Jesus. With or without the doctrine of substitutionary atonement, the teachings and life of Jesus live on in his followers now, and hopefully forever.

This is a tough topic to take on. I am an Evangelical conservative, and I believe that the whole Bible is God’s word, divinely protected and preserved and translated into modern languages for every generation. But you are right about us not knowing quite what to do with all of the OT laws, and we are quite divided about how to deal with the verses about women.
The gospel message is easy: God loves us, Christ died for us, we need to accept His substitutionary atonement to be forgiven. On other matters, the Biblical answers are a bit more confusing, but I think it is tragic the way that Christians have fought and divided into new denominations and subsets of denominations over things like women’s head coverings.
If the bible is inspired by god and infallible and inerrant why do most christians not practise it? The laws of moses are not practised. The teachings of paul on food, women and marriage are generally deemed to be not binding on people today. Liberals like Spong and Borg at least openly state that the bible is outdated and mythical. Trying to live by the bible only leads to confusion about how to live and what to practise. The inerrancy/infallibility beliefs are quite recent and for years the church safeguarded the bible from the masses knowing how difficult it is to interpret and how easy it is to make it say what you want it to. As soon as the bible became readily available the church splintered into a thousand denominations. Substitutionary atonement was not what the prophets said the messiah would achieve. Divine child abuse does fit in with the OT view of god who kills his creation with a flood, with fire and brimstone, with desert wanderings, with soldiers, famine and exile. The Jesus we have in our minds is often different than the god of the OT and the Jesus portrayed in the gospels.
Without Christ’s atonement for our sins, we would be hopelessly lost!