Romans 8:28

All things work together for good to those who love God, to those who are the called according to His purpose.

God's definition of good is that which works to transform us into the likeness of Jesus Christ. Therefore it is possible for a Christian to suffer - such as persecution- and still call it good because God promises that it IS good. If we only look at one point, there are thousands of God-honouring testimonies from Christians who were imprisoned, beaten, or martyred for their faith; of how their trust and love for Christ thrived under the pressure of suffering.