Was it a miracle of God that the Jews incriminated themselves and their children in the blood of Jesus? The Bible said that the Jews as a whole accepted the guilt of killing Jesus and declared guilty themselves and their descendants:


  "When Pilate saw that he was accomplishing nothing, but rather that a
  riot was starting, he took water and washed his hands in front of the
  crowd, saying, 'I am innocent of this Man’s blood; see to that
  yourselves.' And all the people said, 'His blood shall be on us and on
  our children!'" -Matt. 27:24-25


It seems highly incredible that a single person (not to say the whole people) would take responsibility of the lawful execution of somebody they perceived as blasphemist, not to say accept responsibility to their own children.

Do Christians perceive this episode as a God's miracle?
This is not seen as a miracle - but rather an acceptance of the choice they were asked to make.  The Torah specifically disallows children to be punished for the sins of the father - Dt 24:16, so this is nothing but bravado.  In responding "his blood be upon us," they are, in actuality just saying, "there will be no consequence."

When he is being martyred (in Acts 7), however, Stephen picks up on the theme.  He says:


  You stiff-necked people! Your hearts and ears are still uncircumcised. You are just like your ancestors: You always resist the Holy Spirit! 


In other words, even if the vocalizations were not "His blood be upon our children," the sentiment is still the same - Everybody calling for Jesus' execution is acting the same from generation to generation.  They didn't believe the prophets, they didn't believe Jesus.  This is true in every generation, and the sentiment is that in calling for Jesus' death, they expected no different.