Activate Yenna by paying ({2} magic symbol) and tapping it, creating a token copy of Ordeal of Nylea, then untapping Yenna and causing you to scry 2.
Activate Faith Healer by sacrificing the Ordeal of Nylea token.
The Ordeal of Nylea token's second ability triggers, causing you to search your library for two basic land cards and put them onto the battlefield tapped.
When the lands enter the battlefield, Tiller Engine triggers twice, untapping them.
Resolve the Faith Healer ability from step 2, causing you to gain 2 life.
Activate the two lands by tapping them, adding ({2} magic symbol) .
Repeat.
Results
Put all basic lands from your library onto the battlefield.