Having read His Holiness the Dalai Lamas' book 'The Art Of Living'; the final chapter, an address to people of all faiths, addresses his concerns quite succinctly. While he is correct in stating that all religions are not alike, I feel that he has missed the Dalai Lamas' main point, that the underlying tenets of many religions are alike.
While it is true that Buddhism, unlike other religions, is not based around a creator God, it, like many other religions, practises tolerance, compassion and unconditional love for ones' fellow being- a central theme in Judaism, Christianity and Islam. The main core of His Holiness' address is that these Abrahamic religions tend to cause friction among themselves concerning the technicalities of their scriptures, while failing to seek a common ground based on these underlying themes of compassion.
In reference to His Holiness' statement that Christians and others (Or those who were raised in a non- Buddhist culture) need not convert to Buddhism, he refers to this also in his book, by saying that provided the emphasis is placed on the underlying values of tolerance and compassion, it would perhaps be better for those to follow the faiths of their homelands, as these faiths are better suited, culturally, for them to follow, and as such easier for them to assimilate and practise. In this way, it would be possible for all faiths to work together on common grounds, for the spiritual benefit of all.
As for myself, I did not convert to Buddhism, I became one of my own free will, as I did not have another religion to convert from!