1 Timothy 1:13

though I was before a blasphemer, and a persecutor, and injurious: howbeit I obtained mercy, because I did it ignorantly in unbelief;

Blasphemy ... means "speaking against" either God or man; but Paul here means the more serious offense; because, while he did not speak against the Father, he did speak against the Son who is one with the Father.

And a persecutor ... In context this is somewhat of an elaboration upon the preceding word, since it was as "a persecutor" that his speaking against God occurred. New Testament light on Paul's role as a savage persecutor of the church is given in Acts 8:3; 9:1 and Acts 22:19.

And injurious ... "This third word, although the English version obscures the fact, continues the ascending scale of self-condemnation."[29] It indicates a person who takes a savage personal delight and a malicious enjoyment in the afflictions inflicted upon another. Surely no sinner should ever despair of receiving God's mercy if he repents.

Because I did it ignorantly in unbelief ... The fact of Paul's being able to commit so grievous sins against God demonstrates the "pitiable, guilty blindness of sin (Ephesians 4:18; 1 Peter 1:14)."[30] Dummelow perceptively observed on this that "This is an instance of that form of ignorance which excuses acts done through it, ignorance of facts, not of moral principles."[31]

[29] John Wesley, op. cit., in loco.

[30] Wilbur B. Wallis, op. cit., p. 845.

[31] J. R. Dummelow, Commentary on the Holy Bible (New York: The Macmillan Company, 1937), p. 996.