why do bad things happen to good people?

Good people, what do you mean by that? Good people could either be goody two shoes or Christians. Either way things are going to happen to everyone, good and bad alike.  Luke 16:19-26 says

The Rich Man and Lazarus

    ¹⁹ “There was a rich man who was dressed in purple and fine linen and lived in luxury every day. ²⁰ At his gate was laid a beggar named Lazarus, covered with sores ²¹ and longing to eat what fell from the rich man’s table. Even the dogs came and licked his sores.

   ²² “The time came when the beggar died and the angels carried him to Abraham’s side. The rich man also died and was buried. ²³ In Hades, where he was in torment, he looked up and saw Abraham far away, with Lazarus by his side. ²⁴ So he called to him, ‘Father Abraham, have pity on me and send Lazarus to dip the tip of his finger in water and cool my tongue, because I am in agony in this fire.’

   ²⁵ “But Abraham replied, ‘Son, remember that in your lifetime you received your good things, while Lazarus received bad things, but now he is comforted here and you are in agony. ²⁶ And besides all this, between us and you a great chasm has been set in place, so that those who want to go from here to you cannot, nor can anyone cross over from there to us.’

So when bad things happen to you in this life, you need to have God with you so that He can help you through it. Bad things are going to happen to everyone, but this life is short. When you have Jesus in your heart, you can look forward to eternal life that will be full of happiness and rejoicing, no more sorrow and no more pain. If you are going through hard times you need to rebuke the devil because more than likely he is behind all of this. For the devil is here to kill, steal and destroy. No matter how bad he makes things for you, he has no control over you, he reigns over the earth but we have Jesus and Jesus over powers all. Remember to pray and seek the Lord through all these hard times that are going to be coming.