How do Christians respond to this claim in the Qur'an?

How do Christians respond to a claim in the Qur'an that God can not be the father of Christians because God gives them bad things in life to endure? Here is the quote in question set into context: > We also took a covenant from those who said: 'We are Christians'; but they forgot a good portion of the teaching they had been imparted with. Wherefore We aroused enmity and spite between them till the Day of Resurrection, and ultimately Allah will tell them what they had contrived. People of the Book! Now Our Messenger has come to you: he makes clear to you a good many things of the Book which you were wont to conceal, and also passes over many things. There has now come to you a light from Allah, and a clear Book through which Allah shows to all who seek to please Him the paths leading to safety. He brings them out, by His leave, from darkness to light and directs them on to the straight way. Indeed those who said: 'Christ, the son of Mary, he is indeed God', disbelieved. Say (O Muhammad!): 'Who could have overruled Allah had He so willed to destroy Christ, the son of Mary, and his mother, and all those who are on earth?' For to Allah belongs the dominion of the heavens and the earth and all that is between them; He creates what He wills. Allah is All-Powerful. **The Jews and the Christians say: 'We are Allah's children and His beloved ones.' Ask them: 'Why, then, does He chastise you for your sins?' You are the same as other men He has created. He forgives whom He wills and chastises whom He wills. And to Allah belongs the dominion of the heavens and the earth, and all that is between them. To Him is the eventual return.** People of the Book! After a long interlude during which no Messengers have appeared there has come to you Our Messenger to elucidate the teaching of the true faith lest you say: 'No bearer of glad tidings and no warner has come to us.' For now there indeed has come to you a bearer of glad tidings and a warner, Allah is All-Power-ful. - Surah Al-Ma'idah 5:12-19 It seems to say that if he was a loving father he wouldn't make them suffer at times in their lives, i.e. that their circumstances would be different than others.