Paul wants to make certain that the readers do not misunderstand. Just because God will give us freely all things and that all things come from His hand, does not mean that everything will be easy. When we suffer persecution or tribulation, it is being directed by God for our good even though the people doing it mean it for evil. It is still good for the people of God. He wrote that for the name of God, we are like sheep being slaughtered. There is a good purpose for it, but there is no promise that it will be pleasant. The sheep are for the sake of the owner of the sheep. In this case, for the glory of God to be seen and often God's work is most evidence in the response to difficult things. We need to be persuaded that nothing can separate us from God. That everything, things that we like and things that we don't like, are from the hand of God.