God created man good, in his image and likeness (Genesis 1:26-27). Our first parents willfully chose to rebel against God, thereby sinning and introducing death and other negative consequences, including suffering, into man’s earthly existence (see CCC 396ff.).
And yet God does not abandon us amidst our sin and suffering. He sent his eternal Son to redeem and save us (see John 3:16-17). In addition, through his one redemptive Sacrifice of Calvary, Jesus shows how suffering can be redemptive. Similarly, though he does not actively will our sufferings, he can permit them so as to bring about a greater good (see Rom. 8:28), including the opportunity to serve the persecuted (see 1 Cor. 12:12-26; Matt. 25:31-46) and, ultimately, help foster our own ultimate eternal salvation.
For more on the topic of understanding suffering in a Christian context, I recommend our related articles by Dr. Christopher Kaczor, Dr. Peter Kreeft and Trent Horn.