For a deception to work it has to have some familiar elements in much the same way that a counterfeit banknote that is the wrong colour will not be convincing, but one that is reasonably similar looking to the real thing will take people in.

So one thing that some friends have said in Todd Bentley's defence is that he is healing people 'in the name of Jesus'. My reply is

Matt 7:22-23
22 "Many will say to Me in that day, 'Lord, Lord, have we not prophesied in Your name, cast out demons in Your name, and done many wonders in Your name?'
23 "And then I will declare to them, 'I never knew you; depart from Me, you who practice lawlessness!'
(NKJ)

Others have said to me that there is 'fruit' from this ministry meaning I suppose that some are responding to salvation altar calls, but is this lasting fruit.

Biblical fruit is fruit of repentance and fruit that lasts. As in the parable of the sower and the seed that puts down roots rather than showing a flower imnmediately and then later dying. Fruit takes time to appear

Mark 4:28
28 "For the earth yields crops by itself: first the blade, then the head, after that the full grain in the head.
(NKJ)

Fruit appears by due process and time.

Finally, you can know whether to trust a ministry by looking at the life of the minister

Heb 13:7
7 Remember those who rule over you, who have spoken the word of God to you, whose faith follow, considering the outcome of their conduct.
(NKJ)

What is the outcome of their conduct? Kicking people? Tatooing Hindu god of hell Emma-O onto their body? Making rattle snake noises? Babbling like the heathen in their blah, blah, blah prayers? Seeking glory for themselves?