Allah (swt) did indeed intend to save the life of Prophet Jesus (pbuh).
That they said (in boast), “We killed Christ Jesus the son of Mary, the Messenger of Allah”;- but they killed him not, nor crucified him, but so it was made to appear to them, and those who differ therein are full of doubts, with no (certain) knowledge, but only conjecture to follow, for of a surety they killed him not:- … Al-Qur’an, 004.157
This verse says that it was made to appear to them i.e. those who claimed to have killed Jesus (pbuh).
Whose fault is it if people then chose to believe the boastful words of these evil people without first checking other eye-witness accounts of seeing Prophet Jesus (pbuh) alive somewhere nearby at the time of this alleged crucifixion?
And how do Christians know for sure that God did not indeed send angels to save Jesus (pbuh) on that fateful day some 2000 years ago?
And the answer is → Christians don’t… and to be fair, neither do Muslims but at least Muslims are willing to admit that we do not know for sure about the actual events that happened on that day… nor do Muslims care very much to know about it, to tell the truth.