The former footballer, who became a Christian at 18, is now a pastor at Calvary Grace Church in Calgary in Canada, having been to seminary in Alberta after studying tehology at Ridley Hall in Cambridge.
He wrote a book in 2006 about complimentarian views on gender called The Grand Design and is now releasing guides to the three difficult topics for Christians.
Mr Peacock told Premier he was just highlighting what the Bible says: "It's giving clarity because you find clarity in the scriptures and the scriptures have to be our foundation.
"We root our understanding in our creation identity, created male and female, and if you go back to the book of Genesis in the first two chapters, it's very clearly laid out that we were created male and female in the image of God and that marriage is between one man and one woman in covenant for a lifetime and that sexual union is to take place within the covenant of marriage alone.
"If you stick to that, then all kinds of lust, heterosexual or homosexual, is sin if it's outside of marriage, of course it is sin. Heterosexual relationship in marriage is good, homosexual relationship is not good, it is sinful and transgenderism is another step further away from a departure from the binary sexes created in the image of God as rooted and fixed and meaning something and that has moved away now to subjective and fluid and meaning whatever it wants.
"The world is in confusion because when you rip out the first chapters of the book of the Bible, you're ripping out foundations of what it is to be created human, in the image of God, to glorify God and if you rip out the foundations, you're going to be wobbling all over the place and there's going to be repercussions in all spheres of life and we're seeing that now."
Speaking about the fact that many churches now conduct same-sex marriages, he commented: "I mean, that's not Biblical. That's not according to the scriptures. A church that is affirming same sex marriage has ceased to be a Biblical church.
"Of course, all people are welcome to come into the church building and hear the Word of God preached and taught because all people are sinners who need salvation through Jesus Christ alone. That's what we want."
He added he thinks it is different when someone becomes a believer, saying there is a Biblical call to act to please God: "But in Christ there must be repentance in us - that means we don't carry on in the ways that we were before. In Christ we're new creations, forgiven through Christ's work on the cross and his work alone as our righteousness for us and as the one who's taken punishment for us and on the cross, with the Holy Spirit living inside us, now we're new creations."
Stay up to date with the latest news stories from a Christian perspective. Sign up to our daily newsletter and receive more stories like this straight to your inbox every morning.