I wonder why so many Christians are ‘unbelieving’, in other words, do not do anything for religion?

In the place where I live, parishes are discontinued and church buildings closed or they are even bought by Muslims in order to be changed into mosques.

What do you say about the Muslim belief that the text of the Bible has been manipulated? 

Answer:

Faith, as an act of the human person, is a free decision, and in our free societies of the contemporary ‘West’, faith is a decision that demands courage and decisiveness. In former times, many persons went regularly to Church and practiced their Christian faith publicly because most people living in the surrounding neighbourhood did the same. In the German language this practice  is referred to as Milieuchristentum – a Christianity that is composed to a large extent of Christians who follow in their Christian practice and beliefs the majority of the people around them, without much deep personal religious conviction. Today, publicly to profess the Christian faith and consistently to practice it is the fruit of a personal decision and implies going against the mainstream of society in many ways. Furthermore, in the Gospel, Jesus Christ the Lord demands much of those who wish to follow him. He states: “If a person wishes to come after me, let him deny himself and take up his cross and follow me” (Matthew 16:24). The disciple of Christ must not only die to himself but the cross he carries is a sign of his readiness to die to the world. The person who decides to follow Christ and believes in him as Lord puts the relationship with Christ above all natural ties. Furthermore, the true believer in Christ has accepted the possible reality of persecution and that (in which) he may (well) be asked to lose his life (Matthew 23:34). At the same time, however, the cross is also a sign of anticipated glory (John 12:26). In other words, the cross conveys to the sincere follower of Christ, unspeakable inner joy and peace even in this life. Furthermore, following Christ implies the sincere effort to serve one’s neighbour, especially those in need, those treated unjustly, those living on the margins of society, in fact, all people, including those who are not necessarily Christian believers.    

Although in most of  Western society, the number of professing Christians has been diminishing drastically for some time now, many people  of all age groups are sincerely trying to follow Christ in the way I have just indicated.  Many others may no longer be regularly practicing the Christian rites either in public or in private, but in their daily lives and decision-making they are still deeply influenced by the values of the message and example of Christ.

Concerning your question concerning the text of the Bible please consult theme number 1 of the website www.answers-to-muslims.com which discusses the topic: ‘Holy Scripture and the Word of God’ and with the help of the ‘Search function’ you can read all the texts that deal with the Bible and the reliability of the Biblical text.