Everyone's an agnostic. If someone claims not to be agnostic they claim to know everything meaning they know nothing.
We don't "trick" them we allow them to live in ignorance for a short time because unfortunatly, the real world sucks. Atleast for a time being they can have this idea of an inherintly good man, magical in a sense, just going around giving out presents. We don't baby them we just enforce the idea to live in bliss while they can.
It's kind of like if you take a child in poverty and then a child in high wealth, they will act almost no different inately up until the age of like 5. This is simply because children don't differentiate situations as being good or bad if they have no bad to compare it to.