They do not deny his existance or that he was a good man but that is all.They are still waiting for the Messiah.Note what the Bible says:
(Acts 5:34-39) But a certain man rose in the San′he‧drin, a Pharisee named Ga‧ma′li‧el, a Law teacher esteemed by all the people, and gave the command to put the men outside for a little while. 35 And he said to them: “Men of Israel, pay attention to yourselves as to what YOU intend to do respecting these men. 36 For instance, before these days Theu′das rose, saying he himself was somebody, and a number of men, about four hundred, joined his party. But he was done away with, and all those who were obeying him were dispersed and came to nothing. 37 After him Judas the Gal‧i‧le′an rose in the days of the registration, and he drew off people after him. And yet that man perished, and all those who were obeying him were scattered abroad. 38 And so, under the present circumstances, I say to YOU, Do not meddle with these men, but let them alone; (because, if this scheme or this work is from men, it will be overthrown; 39 but if it is from God, YOU will not be able to overthrow them;) otherwise, YOU may perhaps be found fighters actually against God.”
Have you ever thought about how for centuries God's word was opposed destroyed and it's copiers burned as heretics ?Have you ever thought about a little insignificant town of Bethlehem and carpenter's son being so famous he is a household name all over the world?The Bible every year is a best seller and every household can have one if they want it all around the world.That is not by chance. Have you ever read the prophecies in Matthew 24 Luke 21 and Mark 13 ?It is like reading todays newspaper and Jesus spoke these words over 2000 years ago. No man can do that.Jesus fulfilled every prophecy,where he would be born,how he would die,not a bone in his body would be broken at his death,no man can plan such things as these.