Don’t be naïve ..
Non-denominational … is in itself “A Denomination”
The question you need to answer is, do you have faith? Do you know the principles of your own faith? If you have doubts about your own faith, how do you go about resolving these doubts and dealing with them?
Each Christian denomination, especially the major ones, had a specific origin and reasons for its inception. Yes, being born into a certain denomination may not be reason enough to continue holding onto the principles of faith of that denomination. Based on new acquired knowledge and research you may want to tweak your own principles, which automatically moves you into a different denomination that fits your new-found faith.. but, by no means it would imply that suddenly you denounced your faith altogether … it simply moves you from one column to another.. if your new found faith does not agree with any known denomination, you think you can call yourself non-denominational !! and that my friend is complete hogwash .. you have just created for yourself a new denomination .. call it whatever you like, and if two or three or even three hundred agree with you, then your denomination – whatever you like to call it – is your new denomination.
This is true … Unless you lose your faith in Christ and your acceptance of the Bible altogether, in which case you are joining – or even creating – a new religion.. like what happened in the seventh century A.D. when a priest, previously adherent to a heretic form of Christianity (Arianism and in other sources Nestorian) called Waraka ibn Nawfal created the new religion we now know as islam. **
This leads us to the more sensitive issue who goes to heaven, and who goes to hell ?!
Some Christians – from several denominations – like to think that they alone have an exclusive right to go to heaven … everybody else shall surely go to hell !!
So, let me ask you a simple question… who gave you – or me – the audacity to usurp the authority of God to make this eternal decision ?
Is it not better for you – and me – to focus our efforts to keep the principles of our own faith and preserve our own heritage to the best of our ability as long as we believe that this is our way to heaven? If you think that others, who do not belong with you in the same denomination, are lost and need to change their ways.. the only thing you can do, is ask God to help them (as well as you) to find the way of the truth .. you can in a spirit of caring and love – not antagonism and condescending – try to present your case and generate a dialogue where both of you can reach the appropriate end, based on facts and any newly acquired knowledge which conforms to the teachings of the Bible and lessons of history.
Christians – of all denominations – have too many enemies already, spiritual and other otherwise, so we need not create more enemies for ourselves among ourselves .. after all, this is the oldest trick of our enemy to lead us all out of favor with our God.
** check Wikipedia and other historic sources