Are the modern day Christian sects among the people of the Book?

A: Allah (Glorified and Exalted be He) has made lawful to Muslims the food of the People of the Book whether they be Jews or Christians. Allah has also made it lawful for Muslims to marry chaste women of the People of the book. In this respect, Allah (Glorified be He) says: Made lawful to you this day are At-Tayyibât [all kinds of Halâl (lawful) foods, which Allâh has made lawful (meat of slaughtered eatable animals, milk products, fats, vegetables and fruits)]. The food (slaughtered cattle, eatable animals) of the people of the Scripture (Jews and Christians) is lawful to you and yours is lawful to them. (Lawful to you in marriage) are chaste women from the believers and chaste women from those who were given the Scripture (Jews and Christians) before your time (Part No. 22; Page No. 394) Marrying women from among the People of the book is allowed despite the fact that both the Jews and Christians hold such erroneous beliefs as stated in the Ayah (Qur'anic verse): And the Jews say: ‘Uzair (Ezra) is the son of Allâh, and the Christians say: Messiah is the son of Allâh. That is their saying with their mouths, resembling the saying of those who disbelieved aforetime. Allâh’s Curse be on them, how they are deluded away from the truth! The ruling applies to all categories of Jews and Christians whether those who continued to follow Judaism or Christianity at the time the Qur'an was revealed, or those Jews and Christians of today. This is based on the fact that the rulings of Shari`ah (Islamic Law) are general unless there exists something to specify them. Since there exists no such specification regarding the case in question, it is lawful for Muslims to marry chaste women from among the People of the Book. A group of the Prophet's Sahabah (Companions) (may Allah be pleased with them) are reported to have married women from among the People of the Book. Such marriages are preferable at a time when Islam prevails over all other religions and when Muslim husbands are likely to attract the hearts of their wives and children to Islam. However, it is preferable for a Muslim to marry a woman who will be a source of benefit to him in terms of his religion. This is in compliance with the Hadith in which the Prophet (peace be upon him) said, "Choose one who is pious, and your hands will be covered in dust (i.e. You will have the source of all goodness)." A Muslim should avoid marrying women whom he suspects will be a source of harm and threat to his religion such as the present-day women of the People of the Book who are most likely to (Part No. 22; Page No. 395) negatively affect their Muslim husbands and children.May Allah grant us success. May peace and blessings be upon our Prophet Muhammad, his family, and Companions.