Omit "shall be." The meaning is: "The Way of Yahweh," i. e., the Divine Order of the world, has its two sides. It is "strength to the upright, destruction to the workers of iniquity."

The way of the Lord is strength - In the path of obedience the upright man ever finds his strength renewed; the more he labors the stronger he grows. The same sentiment as that in Isaiah 40:31.

The way of the Lord is strength to the upright,.... Who are upright in heart and life; who have the uprightness or righteousness of Christ imputed to them, and right spirits renewed in them; in consequence of which they walk uprightly, Proverbs 10:9. To these "the way of the Lord is strength"; both the way which he himself takes, and the way which he prescribes and directs his people to walk in: the way in which he walks in providence towards them is the strength of them; he is their shade on their right hand; he shows himself strong on their behalf; he is their fortress and strong tower, as the God of providence, even a wall of fire round about them: and the way he takes in the discoveries of his love; in the communications of his grace; in the application of precious promises; by granting the influences of his Spirit; and by leading to his Son, the than of his right hand, made strong for himself and them, is very strengthening unto them: so likewise the way in which he leads his people, the way of his word and ordinances; which, as it is pleasant, so strengthening; the more they walk in them, the stronger they are; they go from strength to strength, they grow stronger and stronger by them; while they are waiting on the Lord in them, their spiritual strength is renewed: moreover, walking in the way of the Lord gives them spirit and courage, and makes them bold and intrepid; so that they fear no enemy, nor any dangers and difficulties, but go on their way cheerfully and pleasantly;
but destruction shall be to the workers of iniquity; not to all that do iniquity, for no man lives without sin; but to those who give up themselves to it, make a trade of it; whose course of life is sinful, and do nothing else but sin; this their way leads to ruin; destruction and misery are now in all their ways, and will be the certain issue of them, even destruction of both soul and body; which will be swift and sudden, come upon them before they are aware, and will be everlasting; it will continue for ever, and there will be no deliverance from it. The Word (x) signifies terror and consternation; and such seize on a wicked man at death, to whom death is the king of terrors; and which will still more strongly possess him when in hell he lifts up his eyes; and also at the day of judgment, when he shall see the Judge coming in the clouds of heaven, sitting on a fiery throne, and shall hear him pronounce him cursed. The clause may be rendered, but the way of the Lord is "terror to the workers of iniquity" (y); the way of the Lord in his works of providence, in which he oftentimes does terrible things in righteousness; and he is very terrible to men in his judgments here, and will be more so in his awful procedure at the last judgment.
(x) "pavor", V. L. Pagninus, Tigurine version, Mercerus, Gejerus; "consternatio", Vatablus, Cocceius, Michaelis. (y) So Mercerus, Gejerus.

The believer grows stronger in faith, and obeys with increased delight.

The way, &c.--that is, God's providence sustains the righteous and overthrows the wicked (Hosea 14:9).

29 Jahve's way is a bulwark to the righteous;
But ruin to those that do evil.
Of the two meanings which מעז (מעוז) has: a stronghold from עזז, and asylum (= Arab. m'adz) from עוּז, the contrast here demands the former. 'דּרך ה and 'יראת ה, understood objectively, are the two O.T. names of true religion. It means, then, the way which the God of revelation directs men to walk in (Psalm 143:8), the way of His precepts, Psalm 119:27, His way of salvation, Psalm 67:3 (4); in the N.T. ἡ ὁδὸς τοῦ Θεοῦ, Matthew 22:16; Acts 18:25.; cf. ἡ ὁδός simply, Acts 9:2; Acts 24:14. This way of Jahve is a fortress, bulwark, defence for innocence, or more precisely, a disposition wholly, i.e., unreservedly and without concealment, directed toward God and that which is good. All the old interpreters, also Luther, but not the Graec. Venet., translate as if the expression were לתּם; but the punctuation has preferred the abstr. pro concreto, perhaps because the personal תּם nowhere else occurs with any such prefix; on the contrary, תּם is frequently connected with ב, כ, ל. לתם דרך, integro viae (vitae), are by no means to be connected in one conception (Ziegler, Umbr., Elster), for then the poet ought to have written מעז יהוה לתם־דרך. 29b cannot be interpreted as a thought by itself: and ruin (vid., regarding מחתּה, ruina, and subjectively consternatio, Proverbs 10:16) comes to those who do evil; but the thought, much more comprehensive, that religion, which is for the righteous a strong protection and safe retreat, will be an overthrow to those who delight only in wickedness (vid., on און, p. 143), is confirmed by the similarly formed distich, Proverbs 21:15. Also almost all the Jewish interpreters, from Rashi to Malbim, find here expressed the operation of the divine revelation set over against the conduct of men - essentially the same as when the Tora or the Chokma present to men for their choice life and death; or the gospel of salvation, according to 2-Corinthians 2:15, is to one the savour of life unto life, to another the savour of death unto death.

The way - The way of God's precepts. Strength - Gives strength, support, and protection.