The God letters were a website feature which ran throughout the latter days of RuneScape Classic and into the early days of RuneScape 2, before being replaced by the Postbag from the Hedge.
The God Letter series soon ended as an entirety- a clear change in direction from the Jagex team. This series had been a staple point in the game worlds developing Lore, and were some of Jagex's first recognizable attempts to further detail the world of RuneScape.
In these letters, players would write in to Jagex with questions addressed to the RuneScape Gods, and Jagex moderators would reply as the gods. As players were not informed which god would reply to each set of questions, players would often address their letters to specific gods, only to get them answered by a different one.
Saradomin had written the first letter, and established himself as the de facto force of "Good" in the new world of RuneScape -
Players had known to look forward to these letters and the occasional accompanying images and concept art over the months - The extra details and curiosities had made the game world of RuneScape 1 (Classic) even more vibrant and full of mystery.
Readers of the Official RuneScape website saw a return to this format when Mod Osborne and Postie Pete began giving extra life to the world in September 2005 via Post Bag from the Hedge - https://runescape.wikia.com/wiki/Transcript:Poultry,_Dragons_and_Zombies
The Gods responded as follows:
Saradomin Letters Edit
Zamorak Letters Edit
Guthix Letters Edit
The letters issues marked with an asterisk (*) were released after the launch of RuneScape 2.