Resurgence (also known as Resurrection) is the magical ability to raise the dead. It is considered more powerful than any of the Seven Wonders, and is oftentimes inaccessible even to some Supremes. It first appears in Asylum and Coven.
Resurgence is a rare power and a tricky one to learn. It is powerful enough to heal the skin of burnt corpses and even fuse limbs not previously attached to the body. The power is useless if the body is in too many pieces. The most notable user is Misty Day, born with this ability; she's the most talented in its use. Misty Day has the ability to resurrect the dead; she killed two crocodile poachers with their own kills, and can revive people fully with their mind and memories still intact, such as Myrtle Snow, Madison Montgomery, and Joan Ramsey. She also has the ability to sense death and corpses, such as when she was beckoned to Kyle Spencer after he was brought back claiming she could 'sense' him, and when she finds the charred corpse of Myrtle Snow, and the body of Joan Ramsey.
If a person is resurrected after a long period of time and suffer injuries, Misty would heal them. She did so through an earth-based formula made of "Louisiana swamp, Spanish moss, and alligator dung" , and merely reattach limbs before the resurrection, like she did with Madison and Myrtle. 
It is true that Marie Laveau could also raise the dead through Necromancy, but it must be noted that there is a distinction between Necromancy and Resurgence. Necromancy does not bring the dead back to life, it simply reanimates corpse and turns them into puppets for the caster. The state of the "risen dead" of Marie, were rotted corpses solely controlled by her. Misty's power of resurgence truly restores life to people.  It is also not to be confused with the Resurrection Spell which can be done by any witch that performs the ritual and incantation, often with undesirable results in accordance with the witch's power and adherence to the spell. 
Resurgence is also often confused with Vitalum Vitalis. However, the difference is that Vitalum Vitalis involves balancing the scales of life and death between the witch and whomever they are using their magic on; Life force can also be drained from someone else and into the witch.  The witch will feel dizziness from the strain of transferring some of their life force to another using Vitalum Vitalis, while they will feel no strain if using Resurgence.