When told to buy swords, the apostles showed Jesus they had two swords among them. Jesus said "That is enough." And they were not to protect anybody from immigrants. When Peter tried to use his sword on the Romans arresting Jesus, Jesus stopped him and healed the ear Peter cut.
The swords were to protect themselves and two was enough for right then so they did not have to rush out and buy more immediately because they were all together.
He stopped Peter because it was time for his sacrifice:
John
Chapter 18
10 Then Simon Peter having a sword drew it, and smote the high priest's servant, and cut off his right ear. The servant's name was Malchus.
11 Then said Jesus unto Peter, Put up thy sword into the sheath:
the cup which my Father hath given me, shall I not drink it?
Defending yourself is not "living by the sword" and dying by the sword is not damnation.
Does he argue for protection?
A slap on the cheek is nothing and Christ's teachings on the mount were to those who were being groomed for leadership positions and had to set a special example they were not intended for the members at large:
[h=3]Matthew
Chapter 5[/h]
1 And seeing the multitudes, he went up into a mountain: and when he was set, his disciples came unto him
13 Ye are the salt of the earth: but if the salt have lost his savour, wherewith shall it be salted? it is thenceforth good for nothing, but to be cast out, and to be trodden under foot of men.
14 Ye are the light of the world. A city that is set on an hill cannot be hid.
15 Neither do men light a candle, and put it under a bushel, but on a candlestick; and it giveth light unto all that are in the house.
16 Let your light so shine before men, that they may see your good works, and glorify your Father which is in heaven.
There is much there that applies to everyone but the extreme restrictions do not apply to everyone, this part for instance:
[h=3]Matthew
Chapter 6[/h]
25 Therefore I say unto you, Take no thought for your life, what ye shall eat, or what ye shall drink; nor yet for your body, what ye shall put on. Is not the life more than meat, and the body than raiment?
26 Behold the fowls of the air: for they sow not, neither do they reap, nor gather into barns; yet your heavenly Father feedeth them. Are ye not much better than they?
27 Which of you by taking thought can add one cubit unto his stature?
28 And why take ye thought for raiment? Consider the lilies of the field, how they grow; they toil not, neither do they spin:
29 And yet I say unto you, That even Solomon in all his glory was not arrayed like one of these.
30 Wherefore, if God so clothe the grass of the field, which to day is, and to morrow is cast into the oven,
shall he not much more
clothe you, O ye of little faith?
31 Therefore take no thought, saying, What shall we eat? or, What shall we drink? or, Wherewithal shall we be clothed?
32 (For after all these things do the Gentiles seek

for your heavenly Father knoweth that ye have need of all these things.
33 But seek ye first the kingdom of God, and his righteousness; and all these things shall be added unto you.
34 Take therefore no thought for the morrow: for the morrow shall take thought for the things of itself. Sufficient unto the day
is the evil thereof.
He also commanded that the wicked be kept separate from the righteous and that certainly applies to those who would deprive us of our liberty:
[h=3]Matthew
Chapter 5[/h]
29 And if thy right eye offend thee, pluck it out, and cast
it from thee: for it is profitable for thee that one of thy members should perish, and not
that thy whole body should be cast into hell.
30 And if thy right hand offend thee, cut it off, and cast
it from thee: for it is profitable for thee that one of thy members should perish, and not
that thy whole body should be cast into hell.
Those who preach suicide Christianity should consider this part:
[h=3]Matthew
Chapter 7[/h]
15 Beware of false prophets, which come to you in sheep's clothing, but inwardly they are ravening wolves.
16 Ye shall know them by their fruits. Do men gather grapes of thorns, or figs of thistles?
17 Even so every good tree bringeth forth good fruit; but a corrupt tree bringeth forth evil fruit.
18 A good tree cannot bring forth evil fruit, neither
can a corrupt tree bring forth good fruit.
19 Every tree that bringeth not forth good fruit is hewn down, and cast into the fire.
20 Wherefore by their fruits ye shall know them.
21 Not every one that saith unto me, Lord, Lord, shall enter into the kingdom of heaven; but he that doeth the will of my Father which is in heaven.
22 Many will say to me in that day, Lord, Lord, have we not prophesied in thy name? and in thy name have cast out devils? and in thy name done many wonderful works?
23 And then will I profess unto them, I never knew you: depart from me, ye that work iniquity.
Their doctrine does not bring good fruit, it brings evil fruit.
The sermon on the mount is also filled with simple instructions that are general and do not cover all of the details or exceptions.