Discernment is the word Christians sometimes use to describe the process of spiritually evaluating and judging truth and goodness.
Discernment may be what leads someone to reject the secular hedonic worldview, to become a Christian (a Mere Christian - or not-denominationally-affiliated Christian), to choose which Christian church/ denomination to join, and perhaps even after that to discern when and where that church or denomination is going astray from the true and the good.
The big problem is that just at the point in history where discernment
is more needed than ever before (due to the collapse of most Christan
traditions and the proliferation of choices/ heresies/ temptations/ Faustian bargains); so
discernment is also at its lowest ever average level...
My feeling is that discernment is "always" sufficient to get someone to
Mere Christianity but that the problem of choosing a denomination, or where truth
lies between denominations (or which is the most truth-full) is very
difficult indeed; and may prove too difficult for most people to unravel with any strong sense of confidence or firmness of faith that they have reached the best possible conclusion.
It is at this point that so many modern Christians are stuck.
Rather than trying to force a swift choice in the face of such difficulties - a choice which is anyway very unlikely to be sufficiently solid as to be binding; I think we can, should, perhaps must, be engaged
in a permanent activity of discernment - that is testing and validating by
reference to one's innermost conviction.
We need to train-ourselves to be alert for signs of uneasiness,
revulsion, disgust, despair etc. which may indicate that we are being led
astray - and for the opposite feelings of deep joy, hope, love etc. which - over
time - are the surest confirmation and guide to the fact that we are in harmony with
I believe (it is my experience) that spiritual progress is possible, and palpable, in terms of the development of one's own discernment - and that such spiritual progress (or depth) is possible even when objectively-observable Christian life may appear to be 'stuck'.