28 And we know that all things work together for good to those who love God, to those who are the called according to His purpose.
The previous two verses expounded on the Spirit’s intercession on our behalf so that our prayers are in the will of God. The succeeding verses (Ro 8:28-30) show the goal of His prayers—conformed to the image of the Father’s Son (Ro 8:29). We can be certain of this goal because the Father predestined us to be like His Son, called us, justified us, and will glorify us. “Hope” is still the theme of the last half of this chapter.
“And” carries the idea of “moreover,” which continues the thought of verse 27. This verse summarizes the chapter and prepares us for the climax of the chapter in verses 37 to 39.
we know [have known]
The Greek word “know” carries the idea of intuitive knowledge. Christians intuitively know that God sovereignly manages the circumstances and events of our lives toward a proper end. This is a common assumption among Christians.
In verse 27 Paul said that “we do not know” what to pray for, but in this verse he says “we know” that God providentially works through every event in our lives. Knowledge is at the basis of our orientation to the plan of God.
Knowledge of the promises of God in the Word of God is the basis for orientation to the plan of God.
The only way we can function with the idea that God providentially works through “all things” is knowledge of God’s statements about it, not through our feelings. We cannot claim a promise without knowledge of it.