Priest is related to Habit. Habit is related to Example. Sample is a type of Example. Sample is a synonym of Try. 
Occasional is a synonym of Casual. Casual is the opposite of Religious. Religious is related to Prayer. Prayer is related to God. 
Priest <--RelatedTo--> Habit <--RelatedTo--> Example <--IsA-- Sample <--Synonym--> Try 
Occasional <--Synonym--> Casual <--Antonym--> Religious <--RelatedTo--> Prayer <--RelatedTo--> God 