1. What makes the disciples martyrdom different from the martyrdom of the ISIS militants? Both truly believe in their cause, both are willing to die or their cause, and both are in a position to know if it is true or not. Couldn't the disciples be as crazy and deluded as ISIS?
This is an interesting question. The confusion comes in with the language that we use. It is one word that describes two different realities. In the Christian world the word martyr comes from the Greek word for "Witness". A martyr in the Christian faith is someone who has witnessed to the Risen Lord to the point where someone takes their life. In the Church this is viewed as the ultimate witness and a certain climax to Christian holiness because one has imitated Jesus Christ in life and in death. So the martyr is one who lays down one's life for Christ and for others.
In the Muslim religion this is not so. The archtype of the Muslim martyr is one who dies while in battle spreading Islam. ISIS would celebrate those soldiers who kill in the name of Allah and the spread of their version of what it measn to be a Muslim (many Muslims disagree with ISIS!). The Muslim martyr is more akin to the Viking concept of the warrior dead that enter Vallhalla than of Christian who dies for others.