It's no secret that the Church of Scotland and Free Church of Scotland don't see eye to eye on how the Christian faith is to be interpreted.

The Free Church continues to look on aghast at what it sees as the continuing liberalisation of the Church of Scotland.

The two Churches have clashed over several issues in recent times, like religious observance in schools and homosexuality.

And now the centrality of Christ can be added to the list after the Moderator of the Church of Scotland General Assembly, John Chalmers, suggested churches don't need to insist on belief.

Writing in the August edition of the Church of Scotland's Life and Work magazine about those currently outside the flock, John Chalmers wrote: "Do not assert that their belonging depends on their ability to tick certain boxes of belief, but ask what would make it possible for them to break into the circle of your church ... Don't insist on belief before belonging – faith comes with belonging.

"I know that in my own life experience the most assured connection with Christ is in the context of being part of the community which is his body."

Free Church minister David Robertson isn't one to sugar-coat his views or dance around the issue, not even for fellow Churches.

He has interpreted not needing to "tick certain boxes" as meaning that they don't need to believe in Christ – and he's horrified by the idea.

Robertson, who is also director of the Solas Centre for Public Christianity, said such a position would be little more than "cuddly toy" Christianity and if that's all the Church of Scotland had to offer, Scots would be better off going to the pub.

"If the Moderator means that non-Christians are welcome in church then he is saying nothing new," he said in response.

"If he is saying that they can be part of the church without believing then it is a statement of incredible desperation to believe that the church will flourish and grow by seeking to attract unbelievers without encouraging them to believe in Jesus."

He said too many people had been brought up in church with a "lukewarm, fuzzy" notion of God but no real understanding of Christ, and that this was only contributing to the decline of the Church of Scotland.

"Instead of presenting this confused old 'church without belief in God' message, as though it were something new, the Moderator would do better to return to the faith of his forefathers and start proclaiming the Good News of Christ as given in his Word," Robertson continued.

"'Believe in the Lord Jesus Christ and you shall be saved' is the message that Scotland needs to hear, not 'come and get a nice warm feeling with us'.

"For that they would be better going to the pub/club or football stadium. The Christian faith is much more radical and life changing."