Marriage is not passive - however, being in love is a passive experience - it is spontaneous, overwhelms us, sweeps us along. And that is a good thing - an ideal thing - so far as it goes...
Marriage (a thing of mature adults, maker of mature adults) needs to be active, the husband and wife need to make an effort - they need to be conscious of what is happening, what are the options - and they need to make choices. Presumably some choices will be made wrong, need to be identified and repented, and so on.
But it is clear that a loving marriage is not sustainable nor will love grow if the husband and wife do not take an active part, are not motivated.
A marriage is a microcosm of Life; because ultimately Life is about love, and about the relationships between entities - men, women, angels (the premortals and the dead), God the Father, and Jesus Christ - for example.
Truth and Reality are a part-of, embedded-in, derived-from this network of relationships - they are not abstractions. They are more like a 'meeting of minds' (and a meeting of bodies) than anything else.
We need both to be in love, and to be deliberately motivated toward love.
'Life's like that'.
We can't be passive in married love, nor in Life; but both need elements of being overwhelmed by impinging reality. We can't merely be active in married love, nor in Life - we are not 'given' marriage and we cannot construct a marriage or the world entirely from our own minds.
(This is good, because we are meant to become free - free in our chosen, loving, eternal 'collaboration' with God's creation.)
It's quite simple really! In Love and in Life we are given half what we need, and the other half we must provide: reality, Life, Truth and Reality are the product. They are not present until both halves are brought together - in the activity we call thinking.
Thinking is necessary to (adult, mature, divine) Love and Life, both.