First. when we look at the passages of Revelation, we can't always take them as literal but in the verses that you sighted, it seems like the Lord is coming to use the sword against those who have already been judged and have no chance at redemption. What I am talking about is that when we talk about self-defense, especially self-defense with a gun, we go into the problem of maybe killing the person while we are defending ourselves. That person who we have just killed, is an image bearer of God that is in need of Jesus. We, the self-defender, already know Jesus and therefore should not be afraid of death and should see this person as our neighbor and not our enemy. If we are truly called to love people like Christ loved people, then that means that we might have to sacrifice our life and if that means we die but the person who kills us will end up knowing Christ because of that, then what greater joy!
Which is basically what happened with Saul of Tarsus.
Acts chapter 26
[
9] I verily thought with myself, that I ought to do many things contrary to the name of Jesus of Nazareth.
[
10] Which thing I also did in Jerusalem: and
many of the saints did I shut up in prison, having received authority from the chief priests; and when they were put to death, I gave my voice against them.
[
11]
And I punished them oft in every synagogue, and compelled them to blaspheme; and being exceedingly mad against them, I persecuted them even unto strange cities.
[
12] Whereupon as I went to Damascus with authority and commission from the chief priests,
[
13] At midday, O king, I saw in the way a light from heaven, above the brightness of the sun, shining round about me and them which journeyed with me.
[
14] And when we were all fallen to the earth, I heard a voice speaking unto me, and saying in the Hebrew tongue, Saul, Saul, why persecutest thou me? it is hard for thee to kick against the pricks.
[
15] And I said, Who art thou, Lord? And he said, I am Jesus whom thou persecutest.
[
16] But rise, and stand upon thy feet: for I have appeared unto thee for this purpose, to make thee a minister and a witness both of these things which thou hast seen, and of those things in the which I will appear unto thee;
[
17] Delivering thee from the people, and from the Gentiles, unto whom now I send thee,
[
18] To open their eyes, and to turn them from darkness to light, and from the power of Satan unto God, that they may receive forgiveness of sins, and inheritance among them which are sanctified by faith that is in me.
I Timothy chapter 1
[
12] And I thank Christ Jesus our Lord, who hath enabled me, for that he counted me faithful, putting me into the ministry;
[
13]
Who was before a blasphemer, and a persecutor, and injurious: but I obtained mercy, because I did it ignorantly in unbelief.
[
14] And the grace of our Lord was exceeding abundant with faith and love which is in Christ Jesus.
[
15] This is a faithful saying, and worthy of all acceptation, that Christ Jesus came into the world to save sinners; of whom I am chief.
[
16] Howbeit for this cause I obtained mercy, that in me first Jesus Christ might shew forth all longsuffering, for a pattern to them which should hereafter believe on him to life everlasting.