Some would say that it is impossible to be a Christian and to be cutthroat based on that definition.   On what basis can that opinion be founded?   

Obviously the first thing that comes to mind to argue against Christians being cutthroat is the injunction for us to do everything out of love.   

No argument there.   But what about these things that our Lord authorized in the OldTestament:
   → The Flood
   → Sodom And Gomorrah
   → GoldenCalf
   → Promised Land

I guess you argue that these are Old Testament citations and are not relevant to the New Covenant.   I will give you that.   

However, listen to some of the things that Jesus said and that the Apostle Paul said in scriptures.   

But when he saw many of the Pharisees and Sadducees come to his baptism, he said unto them, O generation of vipers, who has warned you to flee from the wrath to come? Mat 3:7 John knew the religious folks were there just to critique what he was doing.

O generation of vipers, how can you, being evil, speak good things?     for out of the abundance of the heart the mouth speaks. Mat 12:34 A generation is the set of all people of a particular age group.      Jesus is saying that virtually all the people He was talking to were vipers - cold-blooded snakes only interested in filling their guts.      They were evil and it was impossible for them to speak the Truth.     Their hears were evil and so their speech was evil.      In order for these words the Lord spoke not to apply to us, we must repent and change our minds, our thinking, to that of our Lord Jesus Christ.

You serpents, you generation of vipers, how can you escape the damnation of hell? Mat 23:33 You have rejected Me, the Saviour, so there is no avoiding damnation.

And shall come forth; they that have done good, unto the resurrection of life; and they that have done evil, unto the resurrection of damnation. Joh 5:29 There are two resurrections ahead:    → Resurrection of the just at the appearing of our Lord in the sky    → Resurrection of the damned at the end of the Millennial Kingdom What is the good that we can do?      Receive Christ Jesus as Creator, Lord and Savior.      What is the evil that men do?      They reject the Jesus as Creator, Lord and Saviour.

Then said he to the multitude that came forth to be baptized of him, O generation of vipers, who has warned you to flee from the wrath to come? Luk 3:7 John speaks to the fact that we are all born with a Sin Nature which makes it impossible for us to be good.

From that time Jesus began to preach, and to say, Repent: for the kingdom of heaven is at hand. Mat 4:17 The first and last message that Jesus preached to israel was one of repentance.      Understanding the change; being willing to change and actually changing is repentance.      The Kingdom Of Heaven is the Lord the Holy Spirit who issues from the Spirit Realm into the Physical Realm.

Then began he to upbraid the cities wherein most of his mighty works were done, because they repented not: Mat 11:20 Jesus scolded the people who refused to believe in Him.     no one likes to be scolded.      There are many Christians who would say that scolding is unkind.     But Jesus did it and so should we when a person refuses the Truth.     His scolding was most clearly communicated in this statement:

I came not to call the righteous, but sinners to repentance. Luk 5:32 If a person does not believe they are wrong (i.e.     that they are righteous) then they will not repent.     When a person realizes they are wrong, they will repent.

Woe unto you, Chorazin!     woe unto you, Bethsaida!     for if the mighty works had been done in Tyre and Sidon, which have been done in you, they had a great while ago repented, sitting in sackcloth and ashes. Luk 10:13 His generation saw the Lord do miracles and heard Him preach the kingdom.

I tell you, No: but, except you repent, you shall all likewise perish. Luk 13:3 Though it is not the Lord's will that any perish, it is up to each individual to determine their fate.

Woe unto you, scribes and Pharisees, hypocrites!     for you devour widows' houses, and for a pretence make long prayer: therefore you shall receive the greater damnation. Mat 23:14 religious pretense is an abomination.

Whoever therefore resists the power, resists the ordinance of the Lord: and they that resist shall receive to themselves damnation. Rom 13:2 We are not to be lawless.     lawless people receive punishment in due tine,

If they shall fall away, to renew them again unto repentance; seeing they crucify to themselves the Son of the Holy Spirit afresh, and put him to an open shame. Heb 6:6 If such a true believer turns their back on Christ Jesus they become a destroyer of the testimony of Christ Jesus.     There is no other nor will there be another Saviour.

Repent; or else I will come unto you quickly, and will fight against them with the sword of my mouth. Rev 2:16 He is called to repent by cleaning us the licenciousness and heresy.     The Word Of The Lord contains both blessing and cursing.     Their acceptance of sin would eventually leat to them experiencing the curse.

But though we, or an angel from heaven, preach any other gospel unto you than that which we have preached unto you, let him be accursed. Gal 1:8 Paul curses those who preach a perverted gospel because they are doing the work of Satan.

If there is a significant distinction with respect to being cutthrout between the Old Covenant and the New Covenant is that words replaces swords.   

But, the fact that words like perish, cursed and damnation are used in the New Testament indicates that the consequences of rebellion are essentially the same.   

Why use an evil word like 'cutthroat'?   

'Cutthroat' speaks to the seriousness with which a person goes about achieving their objective.   

Christians are precluded from physical violence in the name of Jesus .   

However, the New Testament scriptures speak of violence in several places.   

And from the days of John the Baptist until now the kingdom of heaven suffers violence, and the violent take it by force. Mat 11:12 The Spirit Realm is the Kingdom Of Heaven.      The anointing upon John the Baptist and the embodiment of the Holy Spirit in Christ Jesus were manifestations of the authority of the Spirit Realm into the Physical Realm.      Both John and Jesus were dealt with violently and were ultimately taken by force and killed.

And a mighty angel took up a stone like a great millstone, and cast it into the sea, saying, Thus with violence shall that great city Babylon be thrown down, and shall be found no more at all. Rev 18:21 There will be no world financial system in the Millennial Kingdom.

(For the weapons of our warfare are not carnal, but mighty through the Lord to the pulling down of strong holds;) 2Co 10:4 Spiritual Warfare is the undercurrent of all the psychological, emotional, moral, political, social and economic turmoil in the world.      No one can escape this warfare.     There is no possibility of being neutral.     The warfare comes to every person, every family, every church, every community, every state and every nation Since Spiritual Warfare is unavoidable, we must first choose sides Jos 24:15, secondly prepare for battle Eph 6:11 and thirdly go forth into the battle Mar 16:15.      In order to fight the good fight of faith we must put on the whole armour of the Lord Eph 6:11.      Once we are properly fitted for defense and protection we are to take up the Sword Of The Spirit - the Word Of The Lord Eph 6:17.      The Word Of The Lord is our offensive weapon.      When wielded in faith under the inspiration of the Holy Spirit it will pull down any stronghold that the enemy sets up.      Without the Word Of The Lord we cannot defeat the enemy.     But when we go on offense with it, we will knock down the Gates Of Hell Mat 16:18.

This charge I commit unto you, son Timothy, according to the prophecies which went before on you, that you by them might war a good warfare; 1Ti 1:18 Spiritual Warfare is played out in the Physical Realm through children of the Lord and children of Satan.

The goal of Violence and warfare is to control or defeat or destroy an enemy.   

In a battle to the death, someone must die, someone will be defeated and someone will win.   

Jesus did not come to the earth suffer and die so that His followers would be defeated.   

The thief comes not, but for to steal, and to kill, and to destroy: I am come that they might have life, and that they might have it more abundantly. Joh 10:10 The thief is Satan who is the inspiration for all the evil in the world.      Whereas the 'I' is Jesus who offers us Eternal Life and Abundant Life.      This verse is a powerful statement contrasting the nature of the enemy with the nature of our Lord Jesus Christ.      Note that the enemy takes by force what is ours, while we must appropriate by faith what is ours in Christ Jesus.      The appropriation is not a 'one and done' thing.     Rather, it is an ongoing process throughout our lives on this earth.      Jesus has given us His life in giving us His Holy Spirit who is in every believer who has asked to be filled.     We aught to invoke His life into every aspect of our walk in the earth.

We see that Jesus did what He did and suffered what He suffered so that we can live abundantly.   

It is impossible to live abundantly when one is under the control, under the attack or being threatened by an enemy.   

I hear the argument: "We can live abundantly in the spirit".   If Jesus were only interested in us living abundantly spiritually He would translate all out of this world at the moment we were Born Again.   

No, the arguments for surrendering the earth to the enemies of Christ are bogus.   It is rooted in the lies of Satan who has stolen our birthright.   

So, if we believers are to be cutthroats and that is not meant physically, what then is our weapon?   
★ The Sword Of The Spirit - WordOfTheLord

This Word aught to be coupled with the power of the Holy Spirit so that:
   → the Gates Of Hell will be broken
   → the devil will be rebuked
   → the devil will be caused to flee
   → those in bondage will be set free
   → the Lord's will is implemented on earth

Physical violence is a reality in the Physical Realm.   It cannot be avoided indefinitely as seen throughout the history of mankind.   

There is a time and place for physical violence in the Physical Realm.   And in warfare men behave as cutthroats.   

As ChildrenOfTheKingdom we are bound to the instructions of the Word in fighting for the Kingdom:

(For the weapons of our warfare are not carnal, but mighty through the Lord to the pulling down of strong holds;) 2Co 10:4 Spiritual Warfare is the undercurrent of all the psychological, emotional, moral, political, social and economic turmoil in the world.      No one can escape this warfare.     There is no possibility of being neutral.     The warfare comes to every person, every family, every church, every community, every state and every nation Since Spiritual Warfare is unavoidable, we must first choose sides Jos 24:15, secondly prepare for battle Eph 6:11 and thirdly go forth into the battle Mar 16:15.      In order to fight the good fight of faith we must put on the whole armour of the Lord Eph 6:11.      Once we are properly fitted for defense and protection we are to take up the Sword Of The Spirit - the Word Of The Lord Eph 6:17.      The Word Of The Lord is our offensive weapon.      When wielded in faith under the inspiration of the Holy Spirit it will pull down any stronghold that the enemy sets up.      Without the Word Of The Lord we cannot defeat the enemy.     But when we go on offense with it, we will knock down the Gates Of Hell Mat 16:18.

But though it is not physical warfare it is serious business.   Either men will be saved or they will be destroyed in hell.   

Lastly, keep in mind whose 'throats' we are cutting.   It is throats of the enemy Satan, his demons and his children among men.   We cut their throats by putting them to silence with the Word Of Truth by the Spirit Of Truth.   

Get in the fight.