Perhaps best known is the 40 years that the Israelites were condemned to wander in the desert before being permitted entry into the Promised Land.
Maybe this mystical quantity will bear significance as we note, this month, the 40th year since the Roe v. Wade decision legalized abortion in America.
Who were they? Who would they have become?
The unmarried graduate student who gave birth to hi-tech impresario and co-founder of Apple, Steve Jobs, may well have aborted this child had her pregnancy occurred in 1973 rather than 1955.
This past week former Rep. Gabrielle Giffords, recovering victim of a crazed gunman, visited, along with her husband Mark Kelly, Newtown, Conn., site of the latest horrible shooting incident.
In their public remarks, they expressed concern that our society has become "desensitized to acts of violence."
Appropriate words, I think, that certainly should be considered in the broadest possible sense in our effort to grasp our willingness to tolerate, even nurture, the open and flourishing presence of evil in our society.
It takes a deadening of the soul to permit this, a state of being "desensitized."
We know it because when those senses are awakened, our indifference and willingness to tolerate evil is pushed back.
When William Wilberforce fought to abolish the slave trade in England, he moved a boatload of the elite into proximity of a slave ship to smell the stench. Their senses were awakened and a major step forward was achieved to end the horror.
Reformed slave trader John Newton composed "Amazing Grace," with the unforgettable line "Was blind but now I see."
If there is good news, it is that, slowly, America seems to be coming to its senses regarding destruction of unborn children.
This week's TIME magazine cover story announces "40 years ago abortion-rights activists won an epic victory with Roe v. Wade: They've been losing ever since."
But in noting that ultrasound has reduced the willingness of Americans to tolerate abortion, author of the story Kate Pickert misses the key point when she writes, "Thanks to prenatal ultrasound, Americans now understand what a fetus looks like and that babies born as early as 24 weeks can now survive."
The key point is that the graphic ultrasound picture, showing the growing and moving fetus, has raised awareness that this unborn child is alive and that abortion is murder.
Ultrasound is sensitizing a desensitized American public that has been willing to tolerate this horror over these 40 years.
Wars are not won overnight. Victory is achieved battle by battle.
Wilberforce did not stop slavery, but he stopped the slave trade.
President Abraham Lincoln's first aspiration was not total abolishment of slavery in America, but making it illegal in new entrants to the Union.
A battle before us now, as the American soul awakens to the evil of abortion, is to end the expropriation of U.S. taxpayer funds, which provide almost half the budget of the nation's largest abortion provider, Planned Parenthood.
According to Rep. Marsha Blackburn, R-Tenn., Planned Parenthood's latest annual report shows receipt of $542 million from U.S. taxpayers. This is outrageous, particularly when every other day we witness a new confrontation in Washington to find ways to cut our trillion-dollar budget deficit.
Blackburn has introduced legislation to end this funding to large abortion providers. Every American should support this and help win this battle.
And we must continue to work to win the war and awaken the American soul, so that 40 years after Roe v. Wade we bring an end to the scourge of legal abortion in America.