Luffy = Sun God
Blackbeard/Davy Jones = Earth God
Imu = Sea God
No idea about the Forest God. As of now there seems to be 3 major factions that have spanned the centuries. The Nika/freedom faction, the Imu order faction, and the Davy Jones chaos faction. Which is the 4th? And no I don't buy Shirahoshi being the Sea God. For one she doesn't have a Devil Fruit, and I doubt Oda would make an Ancient Weapon be one of the 4 gods. In addition, Imu just has so many sea themes aligned with them that it makes sense that they are the Sea God.