When is a Religious Belief Delusional?

[downbeatplumb]

What do you mean by a mathematical object?  That's a term of art, and it's not clear what your question is.

I say that triangularity would exist in potential even if the physical universe had never come into being to manifest objects that sentient organisms would recognize as triangular.  Is my belief in triangularity wrong or delusional?

To have wild speculation in unproven things is healthy. 
To act as thought they are true when the evidence does not support it is delusional.

Religion is all about the second one.