Which proves one does not have to understand the Word of God to perform such acts. They were ignorant. Even Judas was amongst that number. Yet.. They scattered and ran when Jesus was apprehended. They did not even believe Jesus was to be resurrected, even though Jesus taught them he would. They knew nothing.
By their fruit we shall know them? How well they rightly divide the Word of God will be the true fruit.
For when Jesus spoke of knowing someone by their fruit? Jesus was in the process of warning against false teachers. He warned that false teachers will perform miracles and cast out demons, etc. So that's not fruit to be looked for.Performing such acts is not fruit. What they teach and what it produces in others is the fruit. The fruit is how these teacher's followers remain in ignorance, yet think they have more than those who walk faithfully in God's Word in Truth...
For Jesus warned...
Many can know enough knowledge, to know to call him "Lord." Yet not know him.
“Not everyone who says to Me, ‘Lord, Lord,’ shall enter the kingdom of heaven,
but he who does the will of My Father in heaven. 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?’ And then I will
declare to them, ‘I never knew you; depart from Me, you who practice
lawlessness!’ Mat 7:21-23
I have witnessed to hot shots who perform healings... speak in tongues... etc. But when it came to rightly handling the Word of God? Bad fruit. Emotional and unstable followers when challenged by what required rightly handling the Word of God. Stubborn and dogmatic does not equal stability.
God does not want believers IGNORANT of what the Word of God MEANS!
Bad fruit will always be the produce of such teachers. Confident ignorance is the bad fruit.
But the hour is coming, and now is, when the true worshipers
will worship the Father in spirit and truth; for the Father is
seeking such to worship Him." Jn 4:23
Only the truth will make you free. Being healed without gaining sound understanding in knowledge leaves one ignorant of what the Father seeks.
‘Lord, Lord, have we not prophesied in Your name, cast out demons in
Your name, and done many wonders in Your name?’ And then I will
declare to them, ‘I never knew you; depart from Me, you who
practice lawlessness!’
Notice! And they did it all in Jesus name! "In the name of Jesus."
Just like we see today happening.
The Truth will make you free of their claim to the right for authority.