There is a difference between contrary statements and contradictory statements.
Contrary statements are statements that cannot both be true, but both can be false.
Contradictory statements are when either one statement is true or one statement is false.
"All world religions are true" is contrary in relationship with "no world religions are true." Both cannot be true, but both can be false. Both can be false if "Some (or at least one) world religions are true."
Christianity's claim that Christianity is true and that no other religions are true is contradictory with the atheistic position that no world religions are true.
Understanding these two concepts, contrary, and contradictory, can be helpful when addressing the relationship of pluralism, atheism, and historic Christianity.
As before, the information in this apologetic is basically common sense. However, I got the information from Kenneth Samples' book A World of Difference. A list of his book can be found in the slide show below.