Psychology Today has this to say about cults:

Destructive individuals and cults use deception and undue influence to make people dependent and obedient. A group should not be considered a cult merely because of its unorthodox beliefs. It is typically authoritarian, headed by a person or group of people with near complete control of followers. Cult influence is designed to disrupt a person’s authentic identity and replace it with a new identity.

Let’s break this down a little:

Destructive individuals: But those enemies of mine who did not want me to be king over them – bring them here and kill them in front of me (Luke 19.27).

Do not suppose that I have come to bring peace to the earth. I did not come to bring peace, but a sword (Matthew 10:34).

He said to them, ‘But now, the one who has a purse must take it, and likewise a bag. And the one who has no sword must sell his cloak and buy one. For I tell you, this scripture must be fulfilled in me, “And he was counted among the lawless”; and indeed what is written about me is being fulfilled.’ They said, ‘Lord, look, here are two swords.’ He replied, ‘It is enough’ (Luke 22: 36-38). [This is evidently a fictitious episode created around a supposed prophecy (Isaiah 53:12).]

Use deception: The time has come. The kingdom of God has come near. Repent and believe the good news! (Mark 1:14-15). Therefore I tell you, whatever you ask in prayer, believe that you have received it, and it will be yours (Mark 11.24).

Undue influence: Any one of you who does not renounce all that he has cannot be my disciple (Luke 14.33). No one who puts his hand to the plough and looks back is fit for the kingdom of God. (Luke 9.62).

To make people dependent: If anyone comes to me and does not hate his own father and mother and wife and children and brothers and sisters, yes, and even his own life, he cannot be my disciple (Luke 14.26).

…and obedient: If you love me, keep my commands (John 14:15). Whoever serves me must follow me; and where I am, my servant also will be. My Father will honour the one who serves me (John 12.26).

Typically authoritarian… with near complete control: You are my friends if you do what I command you (John 15.14).

Not everyone who says to me, ‘Lord, Lord,’ will enter the kingdom of heaven, but the one who does the will of my Father who is in heaven. On that day many will say to me, ‘Lord, Lord, did we not prophesy in your name, and cast out demons in your name, and do many mighty works in your name?’ And then will I declare to them, ‘I never knew you; depart from me, you workers of lawlessness’ (Matthew 7.21)

Disrupts a person’s true identity: If anyone wants to come after me, let him deny himself, and take up his cross, and follow me. For whoever wants to save his life will lose it. But whoever loses his life for my sake will find it. (Luke 9.23). 

And replaces it with a new identity: Truly I tell you, unless you change and become like little children, you will never enter the kingdom of heaven (Matthew 18.13).

(John said,) ‘He must become greater; I must become less’ (John 3.30).

It is not the healthy who need a doctor, but the sick. I have not come to call the righteous, but sinners to repentance (Luke 5: 31-32).

Whether Jesus said these things or they were put into his mouth by his early followers, it is still the case that if it looks like a cult, talks like a cult and behaves like a cult… it’s a cult.

As it was in the beginning, now and ever shall be.