Can I Command a Scoffer to Be Healed as a Sign to Him?

No.

Jesus never did miracles for scoffers.  A servant is not above his master.  On many occasions, He performed miracles and healings in front of scoffers, but the scoffers themselves never got healed.  A prime example of this is found in Luke 5:17-26.  The power of the Lord was present to heal the scoffers (the Pharisees and doctors of the Law), yet not even one of them got healed as far as we know!  A man who was let down through the roof was the only one who got healed.

Consider the cases in the New Testament where someone asked for a sign:

Matthew 12:38-40:
Then certain of the scribes and of the Pharisees answered, saying, Master, we would see a sign from thee.
But he answered and said unto them, An evil and adulterous generation seeketh after a sign; and there shall no sign be given to it, but the sign of the prophet Jonas:
For as Jonas was three days and three nights in the whale’s belly; so shall the Son of man be three days and three nights in the heart of the earth.

Matthew 16:1-4:
The Pharisees also with the Sadducees came, and tempting desired him that he would shew them a sign from heaven.
He answered and said unto them, When it is evening, ye say, It will be fair weather, for the sky is red.
And in the morning, It will be foul weather to day: for the sky is red and lowring. O ye hypocrites, ye can discern the face of the sky; but can ye not discern the signs of the times?
A wicked and adulterous generation seeketh after a sign; and there shall no sign be given unto it, but the sign of the prophet Jonas.  And he left them, and departed.

Luke 11:16, 29-30:
And others, tempting him, sought of him a sign from heaven.
[Jesus did not perform any sign to answer their request.]
And when the people were gathered thick together, he began to say, This is an evil generation: they seek a sign, and there shall no sign be given it, but the sign of Jonas the prophet.
For as Jonas was a sign unto the Ninevites, so shall also the Son of man be to this generation.

John 6:30-31:
They said therefore unto him, What sign shewest thou then, that we may see, and believe thee?  what dost thou work?
Our fathers did eat manna in the desert; as it is written, He gave them bread from heaven to eat.
[Jesus did not honor this request but again spoke of Himself.]

Luke 23:8-9:
And when Herod saw Jesus, he was exceeding glad: for he was desirous to see him of a long season, because he had heard many things of him; and he hoped to have seen some miracle done by him.
Then he questioned with him in many words; but he answered him nothing.

Jesus was unwilling then to perform signs and miracles just to satisfy the curiosity of scoffers.  He has not changed, so we know that He would be equally unwilling to do so today.

The fact is, Jesus has already performed large numbers of signs and wonders, many of which are documented in the Bible.  If anyone wants to “see” a miracle, he can turn to the Bible.  It is unfair to ask Jesus to do one more sign just because you don’t believe the Bible accounts, to say nothing of the many documented healings that have taken place in our generation.

Jesus was moved with compassion, not with a desire to put on a circus act, when He healed the sick.  He will not stage a sideshow for the benefit of someone who is hostile to the gospel.

It wouldn’t do any good anyway; the scoffer would find some way to explain away the miracle.  “If they hear not Moses and the prophets, neither will they be persuaded, though one rose from the dead” (Luke 16:31).  Jesus did rise from the dead, and scoffers today still doesn’t believe, confirming this verse!

I have known people who have had a miracle performed right under their noses who have not received the Lord.  Miracles are nice for getting the attention of sinners, but the sinners must make their own choices concerning Jesus.  Unfortunately, some stick with their preconceived ideas in spite of an obvious miracle.  Some people love sin too much to want to depart from it.

The bottom line is that a sign or a miracle does not convert an unbeliever.  He is converted when he hears the good news of his salvation and acts on it.  People may think that they need to see a miracle, when what they really need to do is give heed to the Word of God and act on it.