[2 Samuel 22:3]  The God of my rock; in him will I trust: he is my shield, and the horn of my salvation, my high tower, and my refuge, my saviour; thou savest me from violence.

Nails were packed into pressure cookers and exploded at the Boston Marathon.
Those nails were intended to kill and maim the innocent.

These nails were intended to save you!

He was innocent and died to save you!

[Acts 16:31]  Believe on the Lord Jesus Christ, and thou shalt be saved.