Yes and no. In most cases, it is better to have a dried out cigar than a wet one. First let's show you how to get a dry cigar back to normal. A cigar is dried out when too much moisture has escaped the cigar. This is most often not a death sentence, depending on how long the cigar has been exposed to dry air. Try leaving the cigar in a properly set up humidor for about three to four weeks and you should be good to go, but don't try to smoke it beforehand. If you check on your cigar after three to four weeks and it seems better, but not quite fully revived, try leaving it in the humidor a bit longer.
There is also technique where you can "flash humidify" a cigar by putting it in a Tupperware container with a humidification element. Since there is no Spanish cedar lining (like in most humidors) to regulate the humidity and prevent mold, it can over-humidify the cigar and make it even more difficult to bring back. This is very risky and I don't recommend it.
A wet cigar can very often be a difficult problem to resolve. The wetness is not only a guaranteed magnet for mold, it also disrupts the oils and natural effects of the tobacco. If your cigar is too wet, simply leave it in a dry environment for enough time for it to dry out to a smoke-able state. This will only be successful if the cigar has not been over-humidified for a long period of time and is not rife with mold. If the cigar has too much mold on it, it may no longer be smokable. Purchase a digital hygrometer if at all possible. A well calibrated digital hygrometer will ensure that either of the two situations listed above will be very unlikely provided you are paying attention.