Many people criticize any preaching or teaching that is too negative or scary.

They say that you cannot scare someone into heaven.

However the these two lines:

Isaiah 33:14 The sinners in Zion are afraid; fearfulness hath surprised the hypocrites. Who among us shall dwell with the devouring fire? who among us shall dwell with everlasting burnings?

  18 Thine heart shall meditate terror. Where is the scribe? where is the receiver? where is he that counted the towers?

Yet, they are in the context of this line:

Isaiah 33:17 Thine eyes shall see the king in his beauty: they shall behold the land that is very far off.

And even

Mark 9:43 And if thy hand offend thee, cut it off: it is better for thee to enter into life maimed, than having two hands to go into hell, into the fire that never shall be quenched:

  44 Where their worm dieth not, and the fire is not quenched.

is in the context of:

Mark 9:40 For he that is not against us is on our part.

  41 For whosoever shall give you a cup of water to drink in my name, because ye belong to Christ, verily I say unto you, he shall not lose his reward.

They say that there should not be fire and brimstone preaching, but what about?

Revelation 14:10 The same shall drink of the wine of the wrath of God, which is poured out without mixture into the cup of his indignation; and he shall be tormented with fire and brimstone in the presence of the holy angels, and in the presence of the Lamb:

Will they be able to bring a lawsuit against this angel for saying that?