We are approaching the holiest week of the year for Christians, which begins April 15, and presents difficult and life-changing lessons.

The lessons begin on Holy Thursday, when Christ shared the Passover meal with his 12 disciples and then filled a basin with water, wrapped a towel around his waist and bent down and washed their feet.

Washing someone’s dirty, odoriferous feet can be a repulsive thought, but Jesus was revealing there is no action too menial for us to perform.

It was such a shocking gesture for their beloved leader to do, that Peter protested heartily — and only acquiesced when Jesus told him it was essential. “Master, then not only my feet, but my hands and head as well,” Peter exclaimed.

Many people today who work in humble jobs are shunned by those who toil at a desk in a well-appointed office.

How do we treat the people who clean the bathrooms at our jobs and in our churches? Do we know their names and chat with them — or act as if they’re invisible?

What about the stalwart souls who change the diapers of nursing home residents suffering from dementia? How easy it is to shudder and turn away and say, “I would never do that, ever.”

A reporter who saw Mother Teresa cleaning the wounds of a beggar said, “I wouldn’t do what you do for a million dollars.” She smiled and replied, “I wouldn’t either.”

Like many who work in hospitals and nursing homes, Mother Teresa saw Christ in the people she helped. And when she bathed an adult, who had become as helpless as an infant, she recalled his words, “Whatever you did for one of the least of these brothers and sisters of mine, you did for me.”

During Holy Week, we can ask ourselves whether we glimpse Christ in other people — and can we serve them lovingly without feeling this is beneath our dignity?

Jesus was aware that Judas, who was at the supper, would betray him with a treacherous kiss, unleashing a chain of events leading to an excruciating death — but Jesus still washed his feet. We might also ask ourselves whether we would serve someone who wronged us in such a deep way.

Next come the lessons of Good Friday, a day filled with blood, accusations, shouts and tears.

Pilate tried three times to avoid sending Christ to his death, but finally turned Jesus over to the soldiers — and not just for crucifixion.

He was mocked, spit upon, stripped naked and dressed up as a caricature of a king, then beaten savagely and forced to wear a crown of razor-sharp thorns that dug deeply into his flesh.

It’s impossible to imagine the pain he felt when the soldiers drove nails into his hands, as well as his agonizingly slow death from suffocation.

But what remains as a stunning lesson to the world were his words “Father, forgive them, for they know not what they do,” a plea that God would show mercy to his vicious killers.

He didn’t curse the soldiers or call down the wrath of God upon them and their children. How about us? Can we forgive someone who has snubbed us at church — or who’s cheated on us and broken our heart? Can we pray for the ex-spouse and forgive the wrong-doings?

For me, the greatest lesson of Holy Week is that Christ knew about the beatings and the crucifixion ahead of time and didn’t try to avoid them.

Earlier, he explained why: “Greater love has no man than this, that a man lay down his life for his friends.”

We’re the friends Christ suffered and died for, but how hard it is to imitate his forgiveness and love. During Holy Week, let’s pray that with his abundant grace, we can truly follow him — even to the cross.