There is a pernicious argument in circulation in some quarters today that goes along the lines of: planet earth is vastly over-populated by human beings. These rapacious consumers are dangerously depleting the world's finite resources, contributing to climate change, destroying the fragile eco-systems on which life depends, and killing off countless numbers of other species that would otherwise flourish.

Problem: our existence is endangering the continued survival of the planet. Solution: we must not just limit the number of children being born, but we must actively support the extinction of the human race (see here for example).

Sounds a little extreme perhaps, but climate change activists are increasingly calling for curbs on population growth, encouraging people not to have children in order to help save the planet. And some really do support the extinction of the human race.

Counterpointed against this, however, we have the equally compelling problem posed by the catastrophic drop in replacement fertility levels, where it's now recognised that women are no longer having sufficient numbers of children to sustain populations at a healthy level.

It's generally accepted that for any society to survive, there needs to be a replacement level of at least 2.1 children per woman – and even this is tight. Some put the level at 2.3 children per woman. Be that as it may, in the UK at the moment we have a replacement level of around 1.6.

Some countries are far lower – so much so that, globally, 183 out of 195 countries currently have a fertility rate well below replacement level, and it is predicted that by the end of the century the world population will have shrunk by over a billion people.

Climate change activists may think this is something to be celebrated, but the reality is that countries facing such a massive and irreversible decline in their population will increasingly become subject to societal disintegration, escalating violence, and financial collapse - which in turn heightens the possibility of war.

As nations become more dependent on immigration to maintain vital services, the national character of host states will be further diluted, with the result that cultural values will over time become first distorted and then lost. Inevitably, the religious beliefs and values of host countries suffering such ruinous population decline will also over time become lost – leaving religions and cultures with the highest numbers of children and young people clear 'winners'.

In this context, the recent controversy surrounding a tweet by Anglican priest Jamie Franklin is both interesting and concerning, in pretty much equal measure.

Rev Franklin tweeted, "As a priest in the Church of England, I recommend that every married couple has as many children as they possibly can. It is one of life's most wonderful things."

And he finished with a euphoric, "Lo, sons are a heritage from the LORD, the fruit of the womb a reward."

Now you might think that sounds pretty innocuous – the sort of thing vicars are supposed to say. After all, God's command in Genesis to Adam and Eve was to be fruitful and increase in number, and to fill the earth and subdue it. But not a bit of it. Instead, his fellow clergy came out in droves, viciously condemning such insensitive and thoughtless pandering to male patriarchy that would see women relegated to little more than breeding machines.

One reply raged, "This is one of the most pastorally insensitive statements I've seen in a long time. It takes no account of the pain, trauma, and abuse this sort of statement triggers." Another fulminated, "... we should take ecologists seriously when they say we should consider the impact a high population has on the environment."

Are these people for real? Have they not read the Bible? And when there is so much real injustice and suffering in the world, why on earth are they wasting their time so viciously attacking a man who's only offence would appear to be that he takes his faith seriously?

All Christians are called to be 'in' but not 'of' the world, and to be obedient to the teachings of Christ. Those in ministry especially are called to guard the truth, as revealed in the Bible, and to care for and protect the body of believers – to defend them against attack. The ideologically driven 'theories of destruction' and worship of Gaia, put forward by activists who see climate as the new religion, are not just heretical, but imperil the stability of the world.

For the peaceful and healthy continuance of society, as the Rev Franklin says, married couples really should have as many children as they possibly can. And to ensure the continuation of our faith, Christian couples in particular should be obeying God's command to 'be fruitful and multiply'.

Rev Lynda Rose is founder of Voice for Justice UK, a group which works to uphold the moral values of the Bible in society.