Kneeling can be done by using the "/kneel" emote.
Unlike other emotes this one has a special use: Provided the world has the Favor of the Gods, kneeling in front of a god's statue will summon the god's avatar, who may then provide special bonuses, quests or access to restricted areas such as the Realms of the Gods.
Quests[]
Here's a list of the quests that you need to use the Kneel emote:
To get the quests from Glint (after completing the Prophecies Story Line), you must kneel before her, in Droknar's Forge, and her vision (Vision of Glint) will appear.