Many who heard Jesus did not believe His claims to be God. They refused to turn to Him for forgiveness from sin.
Some rejected Jesus and tried to silence Him.
Mark 3:6
And the Pharisees went forth, and straightway took counsel with the Herodians against him, how they might destroy him.
Some follow Jesus to be healed of sickness. They were only interested in the physical benefits they could get from Him.
Mark 3:7-11
But Jesus withdrew himself with his disciples to the sea: and a great multitude from Galilee followed him, and from Judaea, And from Jerusalem, and from Idumaea, and from beyond Jordan; and they about Tyre and Sidon, a great multitude, when they had heard what great things he did, came unto him. And he spake to his disciples, that a small ship should wait on him because of the multitude, lest they should throng him. For he had healed many; insomuch that they pressed upon him for to touch him, as many as had plagues. And unclean spirits, when they saw him, fell down before him, and cried, saying, Thou art the Son of God.
Some thought the claims of Jesus were the claims of a mad man.
Mark 3:20-21
And the multitude cometh together again, so that they could not so much as eat bread. And when his friends heard of it, they went out to lay hold on him: for they said, He is beside himself.
Some accused Jesus of being an evil man possesed by the Devil.
Mark 3:22-30
And the scribes which came down from Jerusalem said, He hath Beelzebub, and by the prince of the devils casteth he out devils.
And he called them unto him, and said unto them in parables, How can Satan cast out Satan? And if a kingdom be divided against itself, that kingdom cannot stand. And if a house be divided against itself, that house cannot stand. And if Satan rise up against himself, and be divided, he cannot stand, but hath an end. No man can enter into a strong man’s house, and spoil his goods, except he will first bind the strong man; and then he will spoil his house.
Verily I say unto you, All sins shall be forgiven unto the sons of men, and blasphemies wherewith soever they shall blaspheme: But he that shall blaspheme against the Holy Ghost hath never forgiveness, but is in danger of eternal damnation: Because they said, He hath an unclean spirit.