Slaying evil was the ‘old Covenant way’.

With the Advent of Christ the Lord, He showed us the Best Way of Agape:

“Overcome evil by Good” (Romans 12:21)

And if needed,

“lay down our lives” (1 John 3:16) instead of “killing the evil ones too” as Christ and His Apostles demonstrated.

Here are the two verses above in ‘full’:

“Do not be overcome by evil, but overcome evil with good” (Romans 12:21)

“We know what love is–through Christ’s having laid down His life on our behalf; and in the same way we ought to lay down our lives for our brother men.” (1 John 3:16)

This the Highest Form of Love (True):

“… Love your enemies …” – Lord Jesus Christ in (Matthew 5:44)

P/S:
Many are praying/searching/hoping to find ‘true’ love; as you just read, ‘true’ love is to ‘love your enemies’ (which will hurt you etc..).

I say, “you probably didn’t know or understand that by asking for ‘true’ love, you may have got it but it’s not the one which you were fantasizing about unfortunately”.

Hence, the walk of ‘true’ Love to even ‘love one’s enemy’ is a battle for His Strongest soldiers of Love.

“Be careful of what you ask, you may actually get it though it wasn’t what you thought it would be“