Bob swings his fungal quarterstaff at the closest undead, moving up as much as he has to in order to attack it.

Shillelagh attack (1d6 bonus necrotic damage on hit): 23 Damage: 18

Finally looking back over his shoulder he sees the damage the swarm of arrows had caused and using a bonus action casts Healing Word on Ban. 

Healing Word (1st level):  7

Round 3:

Bob swings his staff, striking the undead nearest him. The staff, glowing with arcane energies, shatters the bone and armor of the undead and it crumbles to the ground. Satisfied with his felling of the creature Bob turns to Ban and utters the druidic words and Ban's wounds heal some. 

Gimble, from his position trying to keep the door wedged shut, points his finger and utters the arcane words.
U5 save roll: 19
Gimble feels the arcane energy gather then leave his body but, it does not settle upon his intended target.

The remaining undead close to the party attempts to break the grown binding them.
U5 save: 2
U6 save: 2
Both fail and remain stuck.

Again arrows fly towards the party:
Arrow towards Bob: 22
Arrow towards Gillain: 8
Arrow towards Tio: 6
Arrow towards Ban: 17
Arrows miss Gillain and Tio but, strike Bob and Ban.
Bob takes 3 h. p. of damage
Ban takes 6 h. p. of damage.

waiting for Ban to act.

Updated map: https://docs.google.com/drawings/d/1AqpOMOQEjtOvC3uhtiBI4mqwFbXlf4upgKP8yPtM3MM/edit

note: my repost seems to have altered the hp damage taken by Bob & Ban. I had already adjusted the rolls prior to the repost so the original rolls were noted.
With Bob's healing of Ban and the arrow damage, Ban's HP increased by 1
Bob lost 3 hp from his temp HP pool. 

Ban shudders as the eye peers through the cracking door and the voice filled with bloodlust flows over her. She hurriedly says, "Yes, well, I'll keep what of my blood I can. Thanks." Putting herself back against the door with redoubled effort, she takes out a dagger with her left hand and hurls it at one of the restrained skeletons.

Attack: 9 Damage: 8

Sneak Attack: 6

When Bob heals Ban, she sighs in relief in between grunts of effort. "Ah, thank you kind dwarf. A ray of sunshine in this dark time."

Round 3 continued:
Ban launches another of her daggers at one of the entangled undead. Her aim would have been true but there was a sudden bump from the door which threw her aim off.

Tio reaches out with her astral arm, striking the undead in front of her. She strikes the creature and its jaw flies from its hinge, striking the wall then the floor. The creature is damaged but survives the attack. 

Gillain advances a step and attacks the one in front of her and Bob. She thrusts her spear but, misses. She then spins the butt of her spear up and forward and strikes the undead, bone and armor flies up and out and the undead crumbles to the ground.

Again there is a thud at the door, like someone rushing forward and colliding with it. The door structure remains and it does not budge. Ban and Gimble hear scratching coming from the other side of the door.
Updated map: https://docs.google.com/drawings/d/1AqpOMOQEjtOvC3uhtiBI4mqwFbXlf4upgKP8yPtM3MM/edit

Post for Round 4, please. 

Gimble:

Still leaning on the broken pew wedged against the door, Gimble says, "Those skeletons with the arrows are quite irritating, wouldn't you say?" and charges his crystal again with the power of thunder, sending another blast of sound at the skeletons, this time well clear of the church's structure.  He tries to engulf the four skeletons shooting arrows, with any overlap targeted behind them, in case he gets lucky and might damage the creature lurking there.

Shatter DC 13 Con for half, 20 foot diameter sphere, Sonic Damage:  11

Bob barks out a laugh, sounding almost wolfish again for a moment, as his nature-infused staff crashes through bone and rusting armor alike. He steps up to the remaining undead in the doorway and swings with equal gusto, shouting over his shoulder to Ban as he does so. "Thank ye, lass! I hear these undead don' like sunlight much!"

Attack: 19 Damage: 9

He'll also use Halo of Spores to deal 2d4 damage on a failed DC 14 Con save to the remaining undead. 

Halo of Spores: 2

Ban looks to the gnome as she pulls out one of her last remaining daggers and braces the door, "Impeccable aim for something without a brain." With a flick of the wrist, she lobs the knife at the skeleton in the doorway.

The eladrin smiles wistfully at Bob, "Ah, I do miss the sun. Feels like forever since I took a nap in its warmth."

Attack: 22 Damage: 6

Sneak Attack: 10

Gillain will move up to the nearest surviving skeleton and attempt to stab and bash them with her spear…

Attack action: Attack: 11 Damage: 7 (piercing damage)

Bonus attack (polearm master): Attack: 21 Damage: 7 (bludgeoning damage) 

Normally Tio would rush the archers but with a vampire in the church, she instead retreats back towards the siblings.she will disengage from the skeleton.

Round 4:

Bob steps up and with a mighty swing of his staff he causes the remaining close undead to shatter and rusty armor and bone fall to the floor. 

Gimble fires off another Shatter in the midst of the undead archers.
U9 save: 9
U10 save: 15
U11 save: 14
U12 save: 12

The spell goes off and bits of bone and armor flies from each of the undead, some being more damaged than others but all still standing. The undead responds by launching arrows once again.
Arrow 1 toward Bob: 16
Arrow 2 toward Gillain: 15
Arrow 3 toward Tio: 8
Arrow 4 toward Gimble: 15

All 4 arrows fly towards the party but the one aimed at Bob is the only one that hits doing 4 h. p. of damage, but only reduces Bob's temporary hit points.

Tio rushes back towards Ismark and Ireena only to find Ismark unconscious laying on the ground. Tio scans for Ireena but only finds the back door of the chapel open. 

Gillain and Ban may change their actions for round 4.
https://docs.google.com/drawings/d/1AqpOMOQEjtOvC3uhtiBI4mqwFbXlf4upgKP8yPtM3MM/edit

Quote from Hanyouslayer >>

Ban looks to the gnome as she pulls out one of her last remaining daggers and braces the door, "Impeccable aim for something without a brain." With a flick of the wrist, she lobs the knife at the skeleton in the doorway.

The eladrin smiles wistfully at Bob, "Ah, I do miss the sun. Feels like forever since I took a nap in its warmth."

Attack: 22 Damage: 6

Sneak Attack: 10

 Turn redux + rerolls due to enemies without status effects.

Ban looks to the gnome as she pulls out one of her last remaining daggers and braces the door, "Impeccable aim for something without a brain. Say, hold steady for a sec." Quickly, Ban kicks off from the door and rushes to the entrance. With a flick of the wrist, she lobs the knife at the left most skeleton archer. As quick as she left, she returns to the splintering door.

The eladrin smiles wistfully at Bob for just a moment, "Ah, I do miss the sun. Feels like forever since I took a nap in its warmth."

Attack: 9 Damage: 8

Sneak Attack: 5

((OOC: how far away are the skeletons from Gillain? Thanks))

Quote from Grwobert >>

((OOC: how far away are the skeletons from Gillain? Thanks))

 looks to be about 20 to 25 ft.

((Then Gillain would just take her action as described above: move forward and attack the back line of skeletons, getting within 5ft of as many as possible. I think her rolls probably missed, but she wouldn’t have known that before storming forward. Does that work for her? Thanks))

Retreating Tio will shout out abnormally “She’s gone!” She will spend her action looking for any signs of a trail or tracks.

Perception: 18

[My passive is better if it helps, it’s a 14...]

Round 4 continues:
Ban leaps forward and launches her dagger at the far left undead. Her aim is true and she has enough force that once the dagger strikes its target, the undead crumbles to the ground in a heap of bone and rusty metal.

Tio searches but finds nothing she believes are tracks left by Ireena. Tio does notice the back door moves open slightly as there is a flash of lightning and thunder. Large droplets of rain invade the chapel door and into the chapel itself.
Suddenly there is a large gust of wind that comes from the hallway and open front doors that blows through the church. The back door abruptly slams shut from the wind.

Gillain rushes forward to face the undead archers, she finds the ground muddy and slippery. She swings her spear but misses with both tip and butt. 

Thick fat droplets of hard rain pelt Gillain. There is so much water coming down that she has to squint to see. Gillain's eyes are forced close by a blinding flash of lightning. As the thunder washes over the area, Gillain blinks the spots away from her eyes. Once her vision returns, she is shocked at what she sees.
Beyond the 3 undead she faces, Gillain sees at least 2 rows of undead standing unmoved 15 feet beyond where she stands. These are not the same undead she has battled for the last moments. Rainwater runs down their rotting flesh and clothing. They do not move. What movement that does catch Gillain's eye is the giant horned undead stalking forward towards her. 

DM: Post for Round 5.
Notes-Gillain: Due to the heavy rains, lightning, and slippery conditions of the ground, attacks will be made at disadvantage. 

https://docs.google.com/drawings/d/1AqpOMOQEjtOvC3uhtiBI4mqwFbXlf4upgKP8yPtM3MM/edit

((OOC: this is epic! Do the undead attack with disadvantage too? Thanks))

"Gillain! No! Wait fer me!" Bob runs as fast as his stumpy legs will take him toward Gillain as she valiantly rushes the remaining undead. 

(Before I do anything, will I be able to run up next to Gillain? I can only move 25 feet so if I can't actually stand next to her I don't want to cast the Thunderwave spell I have planned!)

Quote from leapingmountain >>

Quote from Grwobert >>

((OOC: how far away are the skeletons from Gillain? Thanks))

 looks to be about 20 to 25 ft.

 reference for your question for Bob's action.