The world leader of conservative Anglicans has warned that the Bible is being turned "upside down" in the move to normalise same-sex marriage.

In a pastoral letter sent out on the same day that the Anglican Church in Canada votes on the issue, the Primate of the Anglican Church in Nigeria, Nicholas Okoh, says: "This is the challenge of the Anglican Communion today.

"The message of the Bible is being turned upside down by those for whom 'my God' means the God I want."

He criticses the vote by General Synod of the Scottish Episcopal Church to change its marriage canon to permit same sex "marriages".

Primus David Chillingworth said he had received assurances from the Archbishop of Canterbury that the Scottish church would still be invited to the proposed Lambeth Conference in 2020.

"Despite the hopes that we had for progress earlier this year, it is clear that the proposed Lambeth Conference seems set to repeat the mistakes of 2008," says Okoh.

The next Gafcon meeting will be in two years in Jerusalem.

"If we are to bear true witness, we must have the same total and loving submission to Jesus as Lord as did Thomas," says Okoh.

"Our struggle in the Anglican Communion today comes about because of those who turn Thomas's words upside down. By 'my' they mean a Jesus who they possess, a Jesus and a Lord who fits with their desires and agrees with what they want as they go with the flow of secular culture."

Recently, Archbishop Foley Beach of the Anglican Church in North America said: "What is tragic about all of this is not just the divisions within the Anglican Communion. What is most tragic is that because of false teaching, millions of souls will not hear the Good News of Jesus Christ, or they will hear a Gospel that appears to be the Gospel, but in reality is contrary to the very Word of God – which is no Gospel at all.

"Souls are at stake. Lives are at stake. Eternity is at stake. It reminds me of what the prophet Isaiah said to the people of his day: Woe to those who call evil good and good evil, who put darkness for light and light for darkness, who put bitter for sweet and sweet for bitter."