A person who rejects the Ahaadith

Q: My best friend who is elder than me (age approx 35) was normal person and use to pray and believe in Quran & Sunnah. He also performed ummrah this year with his family. Last week I meet him and he discussed few things with me on religion which made me surprised. He believes in Quran and everything Quran says. He believes in our Holy Prophet (Sallallahu Alayhi Wasallam) but does not believes in the Ahaadith which are mentioned in different books. As per him, Holy Quran Says right and is a complete book (thats true) but he says ahadees are manipulation by human beings and challenge authenticity of Ahadees. Also he do not believe in praying Salah five times because number of Salah and ways of offering Salah is not mentioned in QURAN. Also he belief Salaah means being close to Allah Ta'ala and do good acts. Also he disrespect different books of Ahadees and (ALLAH TALLAH for give me ) says why DAROOD SHAREEF is not in QURAN which is a complete book and says, DAROOD SHAREF is human made (NO DOUBTS HE COMPLETELY BELIEVES EVERYTHING WRITTEN IN QURAN AND HOLY PROPHET MUHAMMAD (Sallallahu Alayhi Wasallam) IS OUR LAST PROPHET) After knowing his thoughts I am scared if my friend is loosing right path. Also if his thinking and actions can lead him out of Islam. Please tell me the easiest way to bring him back since I am also not a very practising and educated Muslim so I am facing difficulties to do the right thing.

Pleasing one's husband

Q: I just want advice regarding my husband. Don't know what to do. When I go out with him even when I smile at a cousin brother, he gets annoyed and tells me I am committing a sin by smiling at men. Please advise me what is right and wrong.

Studying to become a physical therapist

Q: I am a Muslim (guy) college student. If I study to become a Physical therapist for the sake/pleasure of Allah:

a.) Will Allah accept it?

b.) Does my going everyday to school become a worship (Ammal)?

c.) Does my studying of major subjects,exams,quizzes day and night become a worship?

d.) Can this become a source to gain the pleasure of Allah? And also can this act be included as one of the good deeds that can make me enter Jannah?

Taking an oath that one will become a kaafir upon doing a certain action

Q: I have heard that if a person takes an oath that “If I do this or do not do this, I will become a Kafir forever”. The person becomes a kafir if he or she swore the oath with the belief that he or she would adopt kufr upon its non-fulfillment. Is this true? I would be very grateful if you could please provide a detailed answer for my satisfaction.