The world has never known comfort as we know it today. Millions of us have grown used to luxuries that the ancient emperors never dreamed of, and we’ve come to consider them necessities: motor travel, aspirin, and a warm shower, to name just three.

Compare these to the ordinary miseries endured by citizens in the ancient world. Most lived in cramped, smoky tenements with no ventilation or plumbing. If one of those rooms caught fire, the blaze could consume whole city blocks in minutes; and this was a fairly regular event.

Life expectancy was around 30 for men and lower for women. Hygiene was minimal. Medical care was more dangerous than disease, and disease often left its victims disfigured or dead. The human body was host to countless parasites, and tenements were infested by pests. The bodies of the dead were often left to rot in the town sewer, which usually ran down the middle of the street.

Ancient sources say that the stench from a city could usually be detected from miles away. And country life was worse.

This was the world of the early Christians, the Fathers of the Church, and yet they are as joyful a group as you’ll ever meet. The theologian Hans Urs von Balthasar described the Fathers in this way: “Greatness, depth, boldness, flexibility, certainty, and a flaming love — the virtues of youth are marks of patristic theology.”

Those words do not describe most of us on days when we’re troubled by a hangnail, a malfunctioning air conditioner, or a high pollen count.

Yet Balthasar’s description, as a general statement, is all the more amazing when you consider the discomforts our Fathers faced every day — not to mention their mortal peril from persecution.

Then as now, happiness depended more on a person’s disposition than on his circumstances. What was it that filled the Fathers with such constant joy? “I greet you in the blood of Jesus Christ,” said St. Ignatius Antioch, “which is eternal and abiding joy.”

Jesus’ blood — poured out in His suffering and self-giving, poured out in baptism, poured out in the Mass — was the source of the early Church’s joy. Christians shared His blood and His body, and so they didn’t worry so much about indulging the limitless hungers of their own sensuality. Remarkably, though they suffered extreme deprivation, they exhorted one another to still-greater fasting, so that they might live more perfectly the life of Jesus Christ, sharing in the cross of Christ, His outpouring of love.

They knew something that we perhaps have forgotten. Though they had few comforts in life, they knew they were destined to lose even the few they had.

We should take heed. If we feed our every desire and indulge our every habit as a need and a right, then our losses will leave us bitter and estranged from God. Time, age, illness and “doctor’s orders” can take away our taste for chocolate, our ability to enjoy a cold beer and even the intimate embrace of a loved one. Only the blood of Christ is everlasting joy. “And what else is it to live happily,” said St. Augustine, “except to know that one has something eternally.”

The Fathers were ready to leave everything behind, and do it joyfully. Even today we meet Christians who are able to remain serene amid extreme suffering and even when facing death. It’s not just a matter of temperament. It is the coursing of the blood of Christ, shed for them, the blood of Christ that they’ve taken as their own life’s blood, even as their earthly life drains away.

Like their Fathers in faith, they’ve tasted from the fountain of eternal youth, and that’s all they need to live joyfully amid difficulties.

Today, the media map out many paths to joy. The shelves of the bookstore promise much in The Joy of Cooking, The Joy of Sex, and even The Joy of Linux. The soda machine near my house boasts “The Joy of Cola.” But all joys that pass are false. All joys that pass leave us in sadness, unless they, like the everyday lives of the Fathers and martyrs, are washed in the blood of the Lamb.