This is Holy Week. Each day, a reflection from an "old dead guy" - a church father. For Tuesday, here is Augustine (354-430AD).
You carry the cross of Christ on your forehead. The mark stamped on you teaches you what you should profess. He was hanging on the cross, which you carry on your forehead. Do not delight in the sign of the wood but in the sign of the one hanging on it.
When he was hanging on the cross, he was looking around at the people raving against him, putting up with their insults and praying for his enemies. While they were killing him, the doctor was curing the sick with his blood.
He said, "Father, forgive them, because they do not know what they are doing." These words were not futile or without effect. Later, thousands of those people believed in the one they murdered, so that they learned how to suffer for him who had suffered for them and at their hands.
Brothers and sisters, we should understand this from the sign, from this stamp that Christians receive when they are baptized. From this, we should understand why we are Christians.