And that many Christians cannot agree, even among themselves, what is right and what is wrong according to Biblical teaching.
The homosexual question is an outstanding example.
As I said, we live in a secular world and, if Christians are to survive in it, then we must compartmentalise our lives accordingly.
For instance, as the subeditor responsible for the content and layout of the editorial pages of the New Zealand Herald for 15-odd years, I was regularly required to place comment pieces on the Op-ed page which were diametrically opposed to my beliefs - spiritual, moral, political or whatever.
And at those times I had to remind myself that, at least while I was editing and placing the offending material, I was employed by the newspaper as a journalist, not as a Christian, and the piece received as much care and attention as any other.
However, none of that is to say that Christians should have nothing to do with politics. In fact, a pamphlet has lately been issued, sponsored by a group called the Franklin Christian lobby, and titled Why Christians need to be involved in government.
The pamphlet has been co-authored by two MPs - Chester Borrows, a National Cabinet minister, and Ross Robinson, the Labour member for Manukau East, who is to retire at the election next month - and Christian activist and former United Future MP Gordon Copeland, who lately has joined the Conservative Party.
In a summary, the pamphlet says that God, in His love for humanity, has instituted government so that "the people of the nations may, in a fallen world, live together in harmony and peace".
It says that just as God gave the law, including the 10 Commandments, to the children of Israel at Mt Sinai, law and the punishment of law-breakers is necessary so every citizen understands right and wrong and has a clear set of values to direct and restrain their actions day by day.
Christians, the pamphlet says, have a duty to participate fully in the election of good government, to vote for candidates and parties who will uphold the principles of justice and advance the welfare and happiness of the people; and need to be well-informed and encouraged to participate in government in every way possible.
"Accordingly, we encourage followers of the teachings of Jesus Christ to recognise the role of government and their responsibility as citizens or residents of New Zealand to vote and be informed on the issues of the day, to be open to a vocation in politics or government; to provide counsel to political leaders in the development of policy, to hold governments to account when their actions are inconsistent with gospel principles and to support and pray for those who govern our nation."
And, it reiterates, don't forget to vote.
garth.george@hotmail.com
Garth George is a veteran newspaper journalist, retired and living in Rotorua.