A time of love, and a time of hatred. A time of war, and a time of peace.

A time to love, - hate, - of war, - of peace -
"Love turns to hatred; interest or caprice
Dissolves the firmest knot by friendship tied.
O'er rival nations, with revenge inflamed,
Or lust of power, fell Discord shakes awhile
Her baleful torch: now smiling Peace returns."
The above paraphrase on the verses cited contains a general view of the principal occurrences of time, in reference to the human being, from his cradle to his grave, through all the operations of life.

A time to love, and a time to hate,.... For one to love his friend, and to hate a man, a sinner, as the Targum; to love a friend while he continues such, and hate him, or less love him, when he proves treacherous and unfaithful; an instance of a change of love into hatred may be seen in the case of Amnon, 2-Samuel 13:15. A time of unregeneracy is a time of loving worldly lusts and sinful pleasures, the company of wicked men, and all carnal delights and recreations; and a time of conversion is a time to hate what was before loved, sin, and the conversion of sinners, the garment spotted with the flesh, the principles and practices, though not the persons, of ungodly men; and even to hate, that is, less love, the dearest friends and relations, in comparison of, or when in competition with, Christ;
a time of war, and a time of peace; for nations to be engaged in war with each other, or to be at peace, which are continually revolving; and there is a time when there will be no more war. In a spiritual sense, the present time, or state of things, is a time of war; the Christian's life is a warfare state, though it will be soon accomplished, in which he is engaging in fighting with spiritual enemies, sin, Satan, and the world: the time to come, or future state, is a time of peace, when saints shall enter into peace, and be no more disturbed by enemies from within or from without. In the Midrash, all the above times and seasons are interpreted of Israel, and applied to them.

hate--for example, sin, lusts (Luke 14:26); that is, to love God so much more as to seem in comparison to hate "father or mother," when coming between us and God.
a time of war . . . peace-- (Luke 14:31).

"To love has its time, and to hate has its time; war has its time, and peace has its time." In the two pairs of contrasts here, the contents of the first are, not exclusively indeed (Psalm 120:7), but yet chiefly referred to the mutual relations of peoples. It is the result of thoughtful intention that the quodlibet of 2 x 7 pairs terminates this for and against in "peace;" and, besides, the author has made the termination emphatic by this, that here "instead of infinitives, he introduces proper nouns" (Hitz.).

To love - When God stirs up love, or gives occasion for the exercise of it.