2 Samuel 22:49-50

And that bringeth me forth from mine enemies.

Passing through an opposing medium

Those meteoric stones, which sometimes fall to the earth, but which much more frequently, at certain seasons of the year, are seen shooting across the midnight sky, may also be fragments of the aforesaid world which has perished. These blocks of meteoric matter are flying through space, and when they get within the range of our atmosphere, there is an opposing medium, they have to drive through it at an enormous rapidity, and so they become burning hot, and thus they become visible. And, in like manner, I believe that there are plenty of good men in the world who are invisible till they get to be opposed, and being opposed, and having the love of God driving them on with tremendous momentum, they become red-hot with holy fervour, they overcome all opposition, and then they become visible to the eye of mankind. For my part, I rather like to pass through an opposing medium. I think that we all want to travel in that kind of atmosphere just to give us the sacred friction that will fully develop the powers with which we have been entrusted. If God has given us force, it is not at all a bad thing for us to be put where there is opposition, because we shall not be stopped by it, but shall by that very process be made to shine all the brighter as lights in the world. (The Sciences as Sources of Illustration.).