And we know that in all things God works for the good of those who love him, who have been called according to his purpose. For those God foreknew he also predestined to be conformed to the image of his Son, that he might be the firstborn among many brothers and sisters. And those he predestined, he also called; those he called, he also justified; those he justified, he also glorified.
What, then, shall we say in response to these things? If God is for us, who can be against us? He who did not spare his own Son, but gave him up for us all—how will he not also, along with him, graciously give us all things? Who will bring any charge against those whom God has chosen? It is God who justifies. Who then is the one who condemns? No one. Christ Jesus who died—more than that, who was raised to life—is at the right hand of God and is also interceding for us. Who shall separate us from the love of Christ? Shall trouble or hardship or persecution or famine or nakedness or danger or sword? As it is written: “For your sake we face death all day long; we are considered as sheep to be slaughtered.”
No, in all these things we are more than conquerors through him who loved us. For I am convinced that neither death nor life, neither angels nor demons, neither the present nor the future, nor any powers, neither height nor depth, nor anything else in all creation, will be able to separate us from the love of God that is in Christ Jesus our Lord. - Romans 8:28-39
One of the biggest reasons I hear as to why those around me refuse to believe that there is a loving and wonderful God, is that He allows bad things to happen to good people. My favorite verse to share with them is Romans 8:28. In ALL THINGS, God is working for the good of those who love Him.
It's as simple as that. Evil and darkness are in this world, and bad things are going to happen. When bad things happen to you or your friends, don't forget that God is using them for your good. Death and sickness; depression and anxiety; loss and failure. These will come, but God has a reason that is for your good. HE is good. One of my favorite biblical examples of this is Paul. Once he met Jesus, he never stopped traveling and sharing the good news, and yet, we find out that he dealt with something that God didn't take away from him:
Therefore, in order to keep me from becoming conceited, I was given a thorn in my flesh, a messenger of Satan, to torment me. Three times I pleaded with the Lord to take it away from me. But he said to me, “My grace is sufficient for you, for my power is made perfect in weakness.” Therefore I will boast all the more gladly about my weaknesses, so that Christ’s power may rest on me. That is why, for Christ’s sake, I delight in weaknesses, in insults, in hardships, in persecutions, in difficulties. For when I am weak, then I am strong. - 2 Corinthians 12:7a-10
Delight in your weakness. Remember God's goodness.