Dionysus is mostly known as the patron god of wine, though he was considered the Greek and Roman patron of many titles. This allows critics to make the illogical connection between Dionysus being the god of wine and Jesus drinking wine.
DECEMBER 25 BIRTH There is no record of this date being significant for Dionysus. Like Attis, Dionysus is associated with the annual return of spring.
VIRGIN BIRTH There are two birth accounts concerning Dionysus (neither implies a virgin birth):
Zeus impregnates a mortal woman, Semele, much to the jealously of Hera. Hera convinces Semele to ask Zeus to reveal his glory to her but because no mortal can look upon the gods and live, Semele is instantly incinerated. Zeus then takes the fetal Dionysus and sews him into his own thigh until his birth. Source
Dionysus is the product of Zeus and Persephone. Hera becomes insanely jealous and tries to destroy the infant by sending the Titans to kill him. Zeus comes to the rescue but it's too late- the Titans had eaten everything but Dionysus' heart. Zeus then takes the heart and implants it into the womb of Semele. As we can see, no virgin birth takes place but this is how Dionysus is said to have become a rebirth deity as he is twice born in the womb. Source
TRAVELING TEACHER Dionysus was said to have traveled far and wide (whereas Jesus concentrated His ministry in Judea) to teach men "the secrets of the vine" (how to make wine) and to spread his religious rites. He was never believed to be a spiritual teacher like Jesus.
EUCHARIST To celebrate Dionysus' rebirth after being devoured by the Titans, cult members would take either a live human or animal, tear the victim apart limb by limb, and eat the flesh raw. The sacrifice would be eaten in a cannibalistic manner so the followers could pay homage to their god. However this story relates more to the myths surrounding Tantalus than the Christian communion.
TRIUMPHANT ENTRY Critics claim Dionysus is often pictured as riding a donkey amid crowds waving branches of ivy. However, this is only a description of his regular entourage who traveled with him (not a specific pre- passion entry). These individuals were maenads and satyrs who would follow Dionysus with branches entwined with ivy and grapes- cult symbols representative of the wine god. Jesus on the other hand had a specific triumphant entry upon entering Jerusalem while human crowds waved palm branches (Jewish symbols). I also found a messianic prophecy in Genesis 49:11 (written in approximately 1400 B.C.- way before Dionysus) which foretells Jesus (literally) tethering his donkey with a vine and (symbolically) washing his robes in wine (a reference to His death). Not that I am accusing the Greeks/Romans of creating a deity around a single Bible passage, but if we want to get technical, the Bible groups these three objects together long before Dionysus was a twinkle in the eyes of mythology.
WATER INTO WINE Dionysus was the god of mythology who gave King Midas the power to turn whatever he touched into gold. Likewise, he gave the daughters of King Anius the power to turn whatever they touched into wine, corn, or oil. Considering Dionysus was the god of wine, this should come as no surprise. Regardless, though there are tales where Dionysus supernaturally fills empty vessels with wine, the act of turning water into wine does not occur.
RESURRECTION The "resurrection" account of Dionysus stems from the tale of him being reborn after his attack by the Titans. As we can see, this has nothing to do with the resurrection story of Jesus. Furthermore, we are told after Dionysus completes teaching his followers his religious rites, he ascends to Mount Olympus to be with the other deities- alive and well. His infant rebirth, like Attis, is symbolic of the vegetation cycle- not the atoning of sin.
SIMILAR TITLES The following is a list of alleged titles Dionysus is claimed to share with Jesus. Though in the past we have been able to show some obscure similarities, this list is an obvious fabrication:
King of Kings. Dionysus was only a semi-deity. Zeus was the head god according to the mythology.
Only Begotten Son. Zeus had many relationships with women where he fathered several other children.
Alpha and Omega. Dionysus had a distinct beginning to his existence.
Lamb of God. Dionysus is associated with a bull, serpent, wine, and ivy, but never as a lamb.
The titles I did find for Dionysus are The Bull, The Goat Shooter, The Torch, Dionysus of the Knoll, Meat-Eater, Dionysus of the Vine, and Savior (though the term savior was attributed later to Dionysus for promising carnal pleasure in the afterlife. The only person he saved from Hades was his mother, Semele.).
IN CONCLUSION It is absurd to consider Dionysus as an inspiration for Jesus. Even if the Jews were aware of the fables surrounding Dionysus, it is unlikely they used this lore to create the character for their Messiah.