The words "shall be" in the last clause are a supplement. They are quite unnecessary, and in fact they rather hinder the sense. They destroy the completeness of the antithesis between the two halves of the verse. If you leave them out, and suppose that the "way of the Lord" is what is spoken of in both clauses, you get a far deeper and fuller meaning. It is the same way which is strength to one man and ruin to another, and the moral nature of the man determines which it shall be to him.
I. The "way of the Lord" means here, not the road in which God prescribes that we should walk, but the road in which He Himself walks; or in other words, the sum of the Divine action, the solemn footsteps of God through creation, providence, and history. The same way, the same set of facts, the same continuous stream of tendency, which is all with and for every form of good, is all against every form of evil. God's way has a bright side and a dark. You may take which you like. The way of the Lord must touch yourway. You cannot alter that necessity. Your path must either run parallel in the same direction with His, and then all His power will be an impulse to bear you onward; or it must run in the opposite direction, and then all His power will be for your ruin, and the collision with it will crush you as a ship is crushed like an eggshell when it strikes an iceberg. You canchoose which of these shall befall you.
II. Look at the application or illustration of the principles that are here. (1) The order of the universe, is such that righteousness is life and sin is death. (2) In our physical life, as a rule, virtue makes strength, sin brings punishment. (3) In higher regions, on the whole, goodness makes blessedness, and evil brings ruin. All the powers of God's universe and all the tenderness of God's heart, are on the side of the man that does right. (4) This same fact of the twofold aspect and operation of the one way of the Lord will be made yet more evident in the future. I can conceive it possible that the one manifestation of God in a future life may be in substance the same, and yet that it may produce opposite effects upon oppositely disposed souls. (5) The self-revelation of God has this double aspect: every truth concerning Him may be either a joy or a terror to men. As the very crown of the ways of God, the work of Christ and the record of it in the Gospel have most eminently this double aspect. That which is meant to be the savour of life unto life must either be that or the savour of death unto death.
A. Maclaren, A Year's Ministry,2nd series, p. 279.