Question Summary:
I wanted to know if it is true about khidar a.s,that he is still alive in the sea because he drank such water during his lifetime that would keep him alive forever?2. is a child going to be called by their mothers name or their fathers name on the day of judgement?

Question Detail:

1. I wanted to know if it is true about khidar a.s,that he is still alive in the sea because he drank such water during his lifetime that would keep him alive forever?
2. is a child going to be called by their mothers name or their fathers name on the day of judgement?  

Answer :

In the name of Allah, Most Gracious, Most Merciful
Assalaamu `alaykum waRahmatullahi Wabarakatuh
1.  Majority of scholars testify that Khidir (Alayhi Assalam) is alive.
(Fathul Bari, Vol.6. Pg.536. Qadimi Kutub Khana)   
فقال الأكثرون من العلماء: هو حى موجود بين أظهرنا، وذلك متفق عليه عند الصوفية وأهل الصلاح والمعرفة، وحكاياتهم فى رؤيته والاجتماع به والأخذ عنه، وسؤاله وجوابه، ووجوده فى المواضع الشريفة ومواطن الخير أكثر من أن تحصر، وأشهر من أن تذكر.قال الشيخ أبو عمرو بن الصلاح فى فتاويه: هو حى عند جماهير العلماء والصالحين والعامة معهم فى ذلك.( تهذيب الأسماء واللغات, ج .1 , ص176- 177 دار الكتب العلمية, للعلامة أبى زكريا محيى الدين بن شرف النووى)
2.  There are both opinions on this subject matter.  However the Hadith that indicates to the child being called by his/her father’s name on the Day of Judgment is stronger.  It is also possible that a person will be called by his mothers name due to circumstances, for example Esa Bin Maryam.  As for the father who became a Murtad (renegade) he is not worthy of this honor. 
(Fathul Bari, Vol.10 Pg.689. Qadimi Kutub Khana)
And Allah knows best
Wassalam
Ml. Safraz Mohammed,
Student Darul Iftaa
Checked and Approved by:
Mufti Ebrahim Desai
Darul Iftaa, Madrassah In'aamiyyah