Quite rightly, too, did the Lord after his resurrection entrust his sheep to Peter to be fed. It is not, you see, that he alone among the disciples was fit to feed the Lord’s sheep; but when Christ speaks to one man, unity is being commended to us. And he first speaks to Peter, because Peter is the first among the apostles. Do not be sad, Apostle. Answer once, answer again, answer a third time. Let confession conquer three times with love, because self-assurance was conquered three times by fear. What you had bound three times must be loosed three times. Loose through love what you had bound through fear. And for all that, the Lord once, and again, and a third time, entrusted his sheep to Peter.

There is one day for the passion of two apostles. But these two also were as one; although they suffered on different days, they were as one. Peter went first, Paul followed. We are celebrating a feast day, consecrated for us by the blood of the apostles. Let us love their faith, their lives, their labours, their sufferings, their confession of faith, their preaching.

From a sermon by Saint Augustine
The martyrs had seen what they proclaimed