Tbh, I've pondered this quite a lot; I've had illness all my adult life, have been prayed for for curing countless times, and have experienced other awful things.
The answer I've come to is that if you accept that God has made the world as it is, then it makes sense to accept that God has made the world fragile, vulnerable and eventually dying. God could have made the world other than it is, could have made it (and us) invincible, but (again if you accept a creator God, without denying the process of evolution) God didn't, God made us a funny mixture of strong and weak.
So for me, Christian faith is a way of entering into the meaning of life and, tbh, embracing that weakness as well as that strength and fnding God in the midst of weakness. It's not very sexy, and it wouldn't make any news headlines to say that I was feeling overwhelmed by exhaustion and being a crap mum on Wednesday (which was Ash Wednesday), then I went to church and heard that reading, 'dust thou art, and to dust thou shalt return', I had an ash cross placed on my forehead as a symbol of my weak humanity, and I went home knowing that God holds me in my weakness, my exhaustion and my crapness. We also had an Ash Wednesday vigil for victims of famine, war and poverty, which touched me deeply and made me much more powerfully determined to give to charities this Lent rather than just giving up coffee or somhting banal (it would be banal for me anyway, it can be v. meaningful for others). Then I gave my dd a huge hug and had a good chat with her about her problems at school, and peace came.
Now that's not 'miraculous', is it? But it's my life, and I'm so grateful to have those moments of peace and wholeness in a broken world. One of my favourite bible verses is St Paul's thorn in his side where he says that he praye and prayed for it (whatever it was) to be removed, the he had a moment of knowing that God's strength is made perfect in our weakness. I'm also a huge fan of St Thesesa of Avila, who says that 'Christ has no body now but yours' - in other words, be the miracle for someone else rather than asking for a miracle for yourself. In the feeding of the 5000, Jesus says to his disciples, 'You give them something to eat.' So I see the ongiong poverty on the world as the failure of God's people to do just that, rather than God's failure. It's not sexy, it probably wouldn't win any arguments, but I find that a much more exciting, and profound way of being Christian than asking for miracles all the time.
Cor, that was long - but v. much from the heart!