Can People Who Aren't Saved, Heal in Jesus’ Name?

This question is about salvation first.

Jesus saved you already. There is no Work to be done, or that could be. You have only to accept it.

But you can't accept it unless you believe he can give it.

Like me giving you a car. You'd only consider accepting it if you believe I had the authority to give it to you. If you accept it and trash it, or don't use it, I may have some opinion about that, but it's still yours.

The authority is then given to us to drive it as we will.

Now, even a stranger on the street can tell someone "leave that car alone, it's not yours" They have no right or claim to the car, but are competely able to invoke the authority of its owner in that regard.

Or a stranger say, scraping ice off the windshield. It needs done. They aren't breaking any rules by doing so. Who's to stop them?

I hope that helps

I believe a reason for asking the question is to know if answers to prayer or ability to perform Miracles can be used as evidences to knowing if a person is Saved or not.

Firstly, beleive in Jesus Christ is the main evidence to know if one is really saved or not. Believe is not just a mere knowledge of something but Faith.

He that believeth and is baptized shall be saved; but he that believeth not shall be damned. - Matthew 16:16

For God so loved the world, that he gave his only begotten Son, that whosoever believeth in him should not perish, but have everlasting life. - John 3:16

Salvation is by Faith and is a simple step but the enemy uses complex questions to challenge this.

On the other hand, Miracles can be performed by both the saved and unsaved and cannot be used as an evidence for Salvation.

Miracles are used to build up our Faith personally, or to show the prescence of God in other to propagate the Gospel in a public scenario.

But these are written, that ye might believe that Jesus is the Christ, the Son of God; and that believing ye might have life through his name. - John 20:31

However God appreciates a beleive that isn't reliant on the Miracle evidence but rather ob simple Faith in him.

29Jesus saith unto him, Thomas, because thou hast seen me, thou hast believed: blessed are they that have not seen, and yet have believed.

30 And many other signs truly did Jesus in the presence of his disciples, which are not written in this book:

31 But these are written, that ye might believe that Jesus is the Christ, the Son of God; and that believing ye might have life through his name. - John 20:29-31

Your ‘backstory’ explains several things that will help in offering an answer. Immediately, there appears to be a need for you to learn from Jesus’ own words on this subject, and then to subject everything everyone else tells you to that. There are two particular statements of Jesus that could form a good basis for you to compare all else with.

First, his response to the disciples being upset at some doing miracles, though they were not identified with their group. This is in Mark 9:38-41:

‘Teacher,’ said John, ‘we saw a man driving out demons in your name and we told him to stop, because he was not one of us.’ ‘Do not stop him,’ Jesus said. ‘No-one who does a miracle in my name can in the next moment say anything bad about me…’

Second, his warning to professed Christians on the day of judgement, as to the importance they attached to how they did miracles in his name. This is in Matthew 7:21-23:

‘Not everyone who says to me, “Lord, Lord” will enter the kingdom of heaven, but only he who does the will of my Father who is in heaven. Many will say to me on that day, “Lord, Lord, did we not prophesy in your name, and in your name drive out demons and perform many miracles?” Then I will tell them plainly, ‘I never knew you. Away from me, you evildoers.’

Once you have studied those two passages of scripture and become clear as to what Jesus says about casting out demons in his name back then, and what he says about the day of judgment when false prophets and false miracle-workers are exposed and condemned despite them doing things in Jesus’ name, you might be helped to have a biblical basis for asking questions. Perhaps you might see a need to ask a fresh question on the matter concerning you right now.