If I am walking along the street with a very disfiguring hole in the back of my dress, of which I am in ignorance, it is certainly a very great comfort to me to have a kind friend who will tell me of it. And similarly it is indeed a comfort to know that there is always abiding with me a divine, all-seeing Comforter, who will reprove me for all my faults, and will not let me go on in a fatal unconsciousness of them.
Look how fears have presented themselves, so have supports and encouragements; yea, when I have started, even as it were at nothing else but my shadow, yet God, as being very tender of me, hath not suffered me to be molested, but would with one Scripture or another, strengthen me against all; insomuch that I have often said, Were it lawful, I could pray for greater trouble, for the greater comfort's sake.
You do not really care for God's mercy or His comfort either, so long as you live in any sin. And it is well that you do not; for you can have neither. Your peace will be like a river, when you put away your sin; but not one word of true peace, not one drop of true comfort, can you have till then.
How comforting it is, in view of that inevitable scrutiny of our poor works, to learn that in His patient love He is so leading us and working in us now that He can then find something in it all for which to praise us.
To derive the fullest comfort and encouragement from Romans 8:28 we must realize that God is at work in a proactive, not reactive, fashion. That is, God does not just respond to an adversity in our lives to make the best of a bad situation. He knows before He initiates or permits the adversity exactly how He will use it for our good.
When Christ returned to heaven, He withdrew His physical presence from our sight. He didn't stop being with the disciples but by the ascension fulfilled His promise to be with us to the end of the world. As His body was raised to heaven, so His power and reign have spread to the uttermost parts.