In order to become a disciple you have to forget about yourself. So your appearance is no longer a matter or getting the latest possessions can no longer an issue. Only God can be a priority.
Also, Jesus constantly talked about having to live through suffering if you want o become a disciple. If Christians were being persecuted, how many would stay on through those difficulties. In Africa and in parts of Asia Christians are being persecuted through kidnappings. But, how many Christians in the western world would actually continue with their faith like those in the trouble parts of the world.
Lastly on why this statement may not be true is because the disciples were expected to follow the Ten Commandments. They probably did so but for Christians today, keeping to the Ten Commandments is almost impossible. For example not working on the Sabbath is not really taken into modern day society. Many people with part-time jobs work on the Sabbath. Also ‘Love your neighbour as you love yourself’ is also quite unrealistic be cause you see many murders and discrimination against people. This people may be Christians, in which case they’ve broken the Ten Commandments. Many of the other commandments are also difficult obey for Christians today.
On the other hand Christians are able to make the sacrifices that the disciples did. They were only human beings and they made as many sacrifices in a day as a Christian might make in their entire life. They ordinary Christians who did an extraordinary job, so why can’t Christians today make those same sacrifices? Four of the disciples were fisherman. Why can’t a fisherman today drop his net and follow Jesus.
Another of the commands Jesus gave to his disciples was to go and preach. Christians can do this in many ways. Firstly they could go and preach the Gospel by simply just reading passages and explaining them. Other ways like being part of a charity and building schools and medical centres, a Christian today could also fight injustice and prejudice and do missionary. All Christians who choose this option are putting God first in their lives; this is what discipleship is all about.
On the whole, I don’t agree with this statement. I say this because I think that some Christians, not all can make sacrifices like Jesus’ disciples. However for a Christian today, these sacrifices are very different as to what the disciples made. Christian today will find it harder to make these sacrifices as there are many more temptations in life that so many more others close to you will have.