"If you are an atheist you do have to believe that the main point in all the religions of the whole world is simply one huge mistake.  If you are a Christian, you are free to think that all those religions, even the queerest ones, contain at least some hint of the truth.  When I was an atheist I had to try to persuade myself that most of the human race have always been wrong about the question that mattered to them most; when I became a Christian I was able to take a more liberal view.  But, of course, being a Christian does mean thinking that where Christianity differs from other religions, Christianity is right and they are wrong.  As in arithmetic--there is only one right answer to a sum, and all other answers are wrong; but some of the wrong answers are much nearer to being right than others." Mere Christianity

The wonderful thing about being a "mere Christian" is that you can be open to truth wherever you find it.  As Justin Martyr wrote hundreds of years ago, "All truth, wherever it is found, belongs to us as Christians."  As a mere Christian you can give up the time-wasting botheration of bashing other religions all the time, and also the enervating attempts to prove your one little sect right, and all the others wrong.  One can be open to truth in non-Christian religions, and in Christian denominations other than one's own.

The difference between being a mere Christian and being a universalist, or even a watered-down, nominal Christian is that:

1. You look for truth in the Christian revelation first.
2. You become well-acquainted with that revelation through regular reading and study of the New Testament.
3. Based upon that study you choose a room in the house of Christendom, as Lewis calls it in the preface to Mere Christianity.  You choose a room to settle in, whether Presbyterian, Methodist, Anglican, Baptist, Catholic, Orthodox, or whatever, and then in that room you can receive spiritual meals and enjoy Christian fellowship.
4. As a mere Christian you show kindness and respect to those who have chosen different rooms and to those who still haven't chosen their room in Christ's house.

The life of the mere Christian consists in a constant balancing act between truth and love.  The pursuit of truth will continue to lead you "further up and further in" to the center of one Christian communion.  But the pursuit of love will make you ever broader in your kindness and respect to Christians of all shapes and sizes.  In fact, your love for people of all religions, and no religion, should be ever growing. 

As the Apostle Paul once wrote, as we speak "the truth in love, we will in all things grow up into him who is the Head, that is, Christ" (Ephesians 4:15).

"From the cowardice that dare not face new truth

From the laziness that is contented with half truth

From the arrogance that thinks it knows all truth,

Good Lord, deliver me."

Prayer from Kenya