Then was offered to him one possessed with a devil, blind and dumb: and he healed him, so that he spoke and saw. [23] And all the multitudes were amazed, and said: Is not this the son of David? [24] But the Pharisees hearing it, said: This man casteth not out the devils but by Beelzebub the prince of the devils. [25] And Jesus knowing their thoughts, said to them: Every kingdom divided against itself shall be made desolate: and every city or house divided against itself shall not stand.
[26] And if Satan cast out Satan, he is divided against himself: how then shall his kingdom stand? [27] And if I by Beelzebub cast out devils, by whom do your children cast them out? Therefore they shall be your judges. [28] But if I by the Spirit of God cast out devils, then is the kingdom of God come upon you. [29] Or how can any one enter into the house of the strong, and rifle his goods, unless he first bind the strong? and then he will rifle his house. [30] He that is not with me, is against me: and he that gathereth not with me, scattereth.
Note that Our Lord cast out a devil. A possessed man isn't something that requires supernatural faith to believe in. In the case of a possessed man, the devil is manifesting himself in the physical world. To see a man cast out a demon is evidence of the man's superiority to the demon, and of the man's power in general.
Any sane individual would have acknowledged that Our Lord was a great prophet, the Messiah, and/or God Himself. But what did the Pharisees say?
They violated their own reason, common sense, and all truth by blaspheming against Our Lord. They did this with full malice and bad will.
Our Lord goes on to discuss how some sins are de-facto never forgiven because of the nature of the sin. Obviously referring to the Pharisees, He continues:
[31] Therefore I say to you: Every sin and blasphemy shall be forgiven men, but the blasphemy of the Spirit shall not be forgiven. [32] And whosoever shall speak a word against the Son of man, it shall be forgiven him: but he that shall speak against the Holy Ghost, it shall not be forgiven him, neither in this world, nor in the world to come. [33] Either make the tree good and its fruit good: or make the tree evil, and its fruit evil. For by the fruit the tree is known. [34] O generation of vipers, how can you speak good things, whereas you are evil? for out of the abundance of the heart the mouth speaketh. [35] A good man out of a good treasure bringeth forth good things: and an evil man out of an evil treasure bringeth forth evil things.
Note how Our Lord spoke plainly and called evil, "evil". He didn't focus on their good deeds, ignore the evils they were committing, or anything like that.
Also note: The obstinate Jєωs of Our Lord's time, although they hated him with a passion, the best they could come up with is:
"Those MIRACLES which JESUS is working are done by the power of ..." which implies two things:
1. Jesus obviously existed
2. He worked miracles. They would have been laughed to scorn had they attempted to deny the miracles.
The Modernists today pretend that the Multiplication of Loaves was a miracle of sharing -- everyone opened up their heart, and shared their KFC with their neighbor. If that's all Our Lord did, it would have been much easier to deny His miracles.
No, his miracles were undeniable to anyone who lived at the time. It's only 2000 years later, and after much sinking into darkness, that the modern world dares to allege that Our Lord didn't work miracles, or even that He didn't exist at all.