'Cruel' in the Bible

For news has come to you of my way of life in the past in the Jews' religion, how I was cruel without measure to the church of God, and did great damage to it:

Only it came to their ears that he who at one time was cruel to us is now preaching the faith which before had been attacked by him;

But as in those days he who had birth after the flesh was cruel to him who had birth after the Spirit, even so it is now.