Farming covenant items is a crucial aspect of progressing within the Spears of the Church covenant, especially if you wish to acquire all its unique rewards. The primary covenant item for the Spears of the Church is the Proof of a Concord Kept. However, unlike other covenants, Proof of a Concord Kept is not directly farmed from enemies within the Ringed City itself. Instead, these items are primarily obtained through defeating invaders as a Spear of the Church, or through a more arduous method: farming the Silver Knights in the Anor Londo area of the main game. These knights have a chance to drop Proof of a Concord Kept.
The drop rate for Proof of a Concord Kept from Silver Knights can be quite low, making this a time-consuming endeavor. To maximize your chances, it is highly recommended to equip items that boost item discovery. This includes the Symbol of Avarice helmet, the Covetous Gold Serpent Ring, and consuming a Rusted Coin or Rusted Gold Coin. The optimal farming route involves starting at the Darkmoon Tomb bonfire in Anor Londo and systematically clearing out the Silver Knights in the immediate vicinity. Be prepared for a lengthy grind, as obtaining a significant number of Proof of a Concord Kept may require many runs through this area.
Alternatively, if you are focused on the PvP aspect, actively participating in defending the Ringed City as a Spear of the Church is the most direct way to earn Proof of a Concord Kept. Each successful defense, regardless of whether you defeat the invader or they are defeated by other means, will reward you with these items. While this method is more engaging, it is also less predictable in terms of acquisition speed, as it relies on other players invading your world. For players seeking a guaranteed, albeit tedious, method, the Silver Knight farm remains the primary option.