Why?

By this shall all men know that ye are my disciples, if ye have love one to another. John 13:35, and then John continues his theme.....Greater love has no one than this, than to lay down one’s life for his friends. John 15:13 NKJV

I am puzzled, and not for the first time. Maybe you can help me to understand, so here is my confusion: The overriding theme of the New Testament of the Christian Gospel is love. Love for God, and the supreme love of dying for a friend. Occasionally, the news media carries the story of the extremes of the Christian faith, and the result is that we wring our hands, confess our sins and repent. We usually try to put our failings right, and we use the example of Christ to make ourselves better Christians. the problem is that church attendance in the UK is falling, and people are less likely to believe in God, as they once did. We have sad and unacceptable extremes in the Christian religion, but these are usually well reported and repentance offered.

Then the news media is also filled almost daily on Islamic extremists, or jihadists who have no scruples in taking hostages and life: that is any life (usually ‘western’) who can be used to further their cause. The ongoing situation in Africa where Muslim Islamists openly attack Christian churches, and then say that the loss of any infidel's life is worth it, and within their religious rights. All in the quest for a perfect Islamic state like Iran. You may also be familiar with the recent atrocities in Mali and Algeria where Muslim Islamist jihadists took hostages and their lives to further their aim. These people are truly terrorists in every sense of the word.

Now here is my puzzle. Why is it that the Christian faith of love, repentance and forgiveness is failing, with church numbers in decline, but the active and involved Muslim Mosque population is on the increase? I would have thought that the good base of that religion would desert in droves, so as not to be associated with terrorist activities. After all, these extremists are a very significant part of the Muslim faith group. This much I know (as far as anything can be known) if anything even close to the level of murderous activity was levelled at the door of the Christian Church, there would be very few Christians left to attend any church of any denomination.

So in a nutshell: Why does a barbaric religion grow, but a loving religion fail?