With zeal not arising from the sound knowledge of Jesus Christ ...

Before believing in Jesus,

Saul thought that opposing the name of Jesus of Nazareth

was something worth pursuing vigorously.

He even went to Jerusalem to personally engage in this endeavor.

He received authority from the chief priests

to imprison many saints and consented to their execution.

Furthermore, he went from synagogue to synagogue,

punishing them and compelling them to blaspheme Jesus.

Moreover, consumed with rage against them,

Saul pursued believers even to foreign cities,

causing them trouble

(Acts 26:9-11).

At that time, Saul thought,

"They will do such things because they have not known the Father or me"

(John 16:2).

Saul's zeal for God was not based on the sound knowledge

(Romans 10:2).

Similarly, there may be more Christians like Saul in the future,

whose zeal does not come from a correct understanding of Jesus Christ,

persecuting and even killing those who hope for the return of Jesus.