Answer:
Wa `alaykum as-Salam:
A Muslim of pure belief believes that Isa ibn Maryam, upon our Prophet and
upon both of them peace, will certainly return. The proofs for this are mutawatir
- mass-transmitted - and to reject them is the mark of misguidance and worse.
In addition there are allusive proofs of his return in the Qur'an, among them:
{And He (the son of Mary) shall most certainly be a sign of the Last Hour.
Have no doubt about it!} (43:61).
{There is not one of the People of the Scripture but will believe in him
before his death, and on the Day of Resurrection he will be a witness against
them} (4:159).
Your friend is a person of foul innovation. In addition, she commits kufr
in accusing a Muslim of kufr for believing something which does not justify
such a charge but rather is the truth in which she herself is obliged to believe.
If she is prone to commit such a major sin and will not repent, on top of holding
deviant views, then it is best to get far away from such an evil friend even
if she pleases you.
The reasoning that `Isa, upon him peace, did not know that Christians would
commit polytheism after him is unrelated to his descent from heaven at the end
of times. Muslims believe that Allah Most High spares His Prophets knowledge
of the kufr of their followers after they leave this life, even as He may make
them aware of all their other states. The good and bad deeds of this Umma are
shown to the Prophet, upon him peace, in Barzakh, but not the apostasy of individuals
so as not to harm him.
The difference of opinion whether `Isa died or was raised to the heaven alive
and in the body, is also unrelated to his descent at the end of time.
Regardless of everything else Jesus WILL descend from the heaven. He will
destroy the cross and kill the swine. The sincere among the Jews and Christians
will enter Islam at his hand while the insincere will deny him and join the
Dajjal - the Arch-Liar. He will renew the Shari`a of our Prophet Muhammad and
kill the Dajjal. He will marry and have children and die together with the last
band of believers left on earth, after which the Hour will rise. This is our
Sunni faith and whoever wishes to disbelieve let them disbelieve.
Pure Muslim belief in relation to deviant pseudo-Muslim belief in the time
we live in, is dearer and rarer than Islam itself in relation to other creeds.
Cling to the faith of the pious predecessors and leave all the rest as so much
smoke and whisperings.
Hajj Gibril