Truth versus Christianity - which ought to come first?

He, who begins by loving Christianity better than Truth, will proceed by loving his own Sect or Church better than Christianity, and end in loving himself better than all.

Aphorism XXV - from Aids to Reflection by ST Coleridge

Coleridge's aphorism is true - but...

The "but" comes from something about Truth that is apparent to us now, in a way that was not to STC a century ago. 

This "something" is that Truth - as Coleridge meant it - is rooted in Christianity; such that the modern post-Christian/ secular idea of Truth has been fatally weakened as a personal motivator; even when it has not been altogether demoted to insignificance, or inverted to serve expediency. 

In other words; Coleridge is actually drawing a distinction here between what might be termed fidelity to divinely-created reality (which is what STC calls Truth); and the diktat of what official Church authorities happen currently to be asserting (which is what STC calls Christianity). 

Coleridge is implicitly stating the Romantic recognition (optional then, unavoidable now) that our personal conviction of Truth does and should have priority over institutional aspects; or that individual discernment and judgments are primary; and organizational statements are secondary. 

More simply still: 

We are each-of-us necessarily and unavoidably responsible for the content of our religion.