There are some which can be finished with sparks directly and some which can be done with sparks + other tasks.
The ones which can be directly finished are:
Hunters of Fortune - Requires 7 sparks to receive the Medal of Worship.
Juggernauts - 1 spark gets the players 7 liros, if a player wants to receive the medal of worship immediately after getting to 3k reputation, it'll cost them 29 Sparks, if not, it'll be between 1 to 29.
Custodians of Magic - The player can give Barachmung the Chronicler 20 sparks to receive the Medal of Worship.
That's all there is to receiving the Medals of Worship directly. There are also reputations which require the players to do more than giving sparks of heavenly fire.
Underground Knights - To be able to receive the Medal of Worship, the player will need to get all 3 certificates of underground knights. 2nd certificate requires players to receive 1 to 10 tournament of worship wins, if they decide to not do it, they can give 20 sparks immediately or go with a mixed approach to get x amount of wins and hand in 20-(x*2) amount of sparks (1 win=2 sparks) to receive the 2nd certificate. 1st and 3rd certificates are still required and they can't be received with sparks.
Great Battles - Similar to Underground Knights reputation. Players need to get 3 pieces of quest items, one from dragon altar, one from Aladeya and one from God of the Cursed and the Undead. The Dragon piece is harder to get (1k great battle wins or 100 great battle leadership achievement + 30 imp combo cubes, 5 demon combo cubes and 1 devil combo cube), therefore players can give 20 sparks to omit all of this. But they'll still have to receive Aladeya and God of the Cursed and the Undead pieces by giving these altars whatever item quest requires and do their fights.
Last, but not least, Pet Patrons. A player who received 3000 reputation of pet patrons reputation can talk to the reputation NPC and give them 7 sparks to receive 500 vital substances, however they'll still have to carry out the rest of the quest (handing in other resources like combo cubes, pure eldorill crystals etc.) and in the end, fight with Belinda.