I came up with this idea a while ago and am just now looking at working out the kinks so I can make it as an Adventurer's League character in the Rage of Demons season.
Basically, he's a human (variant) Life Cleric with the Magic Initiate feat and the Charlatan background. For his Magic Initiate picks, he will take Shocking Grasp and Firebolt as Sorcerer cantrips, along with Mage Armor. He will sell his light crossbow and chainmail in order to buy a hand crossbow.
I have his stats as STR 8, DEX 15(+1), CON 10, INT 8, WIS 15(+1), CHA 14.
I see his level progression as follows:
1 - Cleric
2 - Sorcerer
3 - Cleric
4 - Cleric
5 - Cleric - ASI: Bump WIS +2
6 - Sorcerer - (Sorcery Points start here)
7 - Sorcerer - (Empowered Spell and Extended Spell)
8 - Cleric
I haven't decided past this point.
What I am wondering is
What deity should he worship? Again, this is for Adventurer's League, so Forgotten Realms deities only.
Is there a better way to represent him as a Sorcerer by staying completely Life Cleric? Yes, I realize I can "refluff" spells as whatever I want. 
Any other comments or critiques are welcome.
Maybe Favored Soul ends up in the new book?
If I understand things correctly, the goal is to pretend to be a Sorcerer while having healing, not necessarily to be a Sorcerer or having the primary healing come from Cleric. Have you considered Lore Bard? A Lore Bard X/Life Cleric 1 is reasonably straightforward and Magical Secrets will give you access to both boom and buff in a reasonable time frame...
Why life cleric? Are you open to other options like Tempest domain for example?
Wait, he's pretending, but at level 2 he'll no longer be pretending? What's the point of going through Magical Secrets when he can just pick them up in 1-2 sessions? Trickery Domain sounds like something a Charlatain would be into.
Also, a Human with little or no access to Darkvision in the Underdark is definitely a bad idea if you ask me.
if you actually dip levels into sorcerer, i don't really see how you're pretending to be a sorcerer =P
also there already something what you're looking for... Unearthed Arcana has the Sorc Origin; Favored Soul
as for deities well... worship Mystra, goddess of Magic, or Azuth her "lieutenant" and god of wizards
even they have clerics that serve them, although most of their servants are usually sorcerers or wizards.
Sorc FS 1 / Cleric X mellored's guide goes Light or Tempest ... and
start praying to Thor to give you juicy blaster spells to make items with.
awaken_D_M_golem wrote:
Mommy_was_an_Orc wrote:
bid wrote:
jaappleton wrote:
bid wrote:
You're not really pretending to be a sorcerer if you have sorcerer levels.
Go straight cleric with the trickery domain for flavor. Then just RP it. The other players at your table will know you aren't a sorcerer anyway and they would be the only ones you need to use class abilities to fool.
I was tempted to just take the one level dip in Sorc for this, which would allow me to use the Mage Armor spell from Magic Initiate with spell slots in case we have a greater than 8 hour adventuring day.
Unless and until Favored Soul is no longer Unearthed Arcana, I can't consider it because I want this character to be Adventurer's League legal, which means no UA stuff,
My original plan was to take the Light domain which offers spells which a Sorcerer might have and would still allow me to have healing spells and act like a Cleric. But as I went through my fake progression, I realized that having three levels of Sorcerer would give me 3 SP and metamagic options, which could mean a bonus action Cure Wounds and a Fire Bolt in a turn, instead of relying on Healing Word.
Undrhil wrote:
Mommy_was_an_Orc wrote:
Undrhil wrote:
Danny_Montanny wrote: