There is pain and sorrow in life. The world is fallen. These will not disappear until God's Kingdom is established. But Satan still plans to add to our misery.
Too often our experience of pain and sorrow become more real and more consuming than our experience of God's presence. So, Satan does not just seek to inflict pain. He seeks to divert our attention to it. His purpose is fulfilled if God's children are more taken up with how bad something is, than how good God is, and how great his resources are. He gets his way if God's children spend more time complaining about something bad happening, than seeking him and listening for how he speaks into it and how we should respond.
Ultimately, spiritual warfare is encountering "something", and then seeking God for his response to this "something" and obeying God in that response. We keep our hearts engaged with God's heart. Satan's purpose is to separate us from God's presence.