How does Shakespeare express his views on close relationships in Sonnet 116?

In Sonnet 116, the speaker asserts that those who truly love each other are constants in each other's lives. When anything attempts to "remove" the closeness in the relationship, love perseveres. The speaker uses a metaphor of a tempest to describe how love overcomes the tumultuous changes:

It is an ever-fixed mark
That looks on tempests and is never shaken

Those in loving and close relationships therefore use their love as an "ever-fixed mark" to guide them through the storms of life. True and meaningful relationships are not "shaken" by those rough times because the relationship serves as the metaphorical North Star, always providing guidance and direction:

It is the star to every wand'ring bark

This metaphor relies on nautical imagery, aligning a true relationship to the guidance provided to sailors on their journey via the constancy and never-changing position of the North Star.

Those who enjoy a meaningful and loving relationship do not watch it fade over time. Even when life's circumstances take them "to the edge of doom," the relationship remains steadfast and true.

The speaker asserts that love is eternal. It is steadfast and constant. It doesn't change with circumstances or when situations are not as favorable. Love provides a solid place to ground oneself in the difficulties of life. This is primarily conveyed through metaphors and a tone of firm hope.

What were Shakespeare's personal views on love in Sonnet 116?

If you are studying Shakespeare in much detail you will find, if you haven't already, that when you attempt to ascertain anything "personal" about him, such as your question about his "personal feelings about love," there are a wide variety of opinions. Some, if not most, think of Shakespeare as a very talented and prolific individual. Others, however, because of the amount and variety of work that bears the name "Shakespeare," believe that there was no one person by that name but that various authors wrote using the same name. This and the lack of personal materials (personal writings, letters, etc.) make the determination of "his personal feelings" about anything impossible to ascertain. But that is another consideration.

In Sonnet 116 as in many other works, Shakespeare sees love as something transcendent—not something that might happen as a result of relationships and circumstances but the motivation for the relationships in the first place. Love is seen as an ideal, a virtue, a soul-task that is the result of mental and spiritual effort.

What language does Shakespeare use to show the importance of a relationship in Sonnet 116?

William Shakespeare's Sonnet 116 provides a definition of love. Curiously though, Shakespeare does not tell readers what love is by defining what it is; instead, Shakespeare defines love by defining what it is not.

The language he uses is one which speaks to the defining of something through the things which cannot align with it. (Sounds different, but (sometimes) one's knowledge of what something is not allows them to identify what something is). For example, milk is not a fruit because it does not grow on trees, it does not have seeds, and it does not qualify as a solid.

Therefore, according to the sonnet, love is defined by the things which it is not: love is not something which can be altered, bent, or removed. Love is not wandering, shaken, or "Time's fool." By identifying what love is not, one can identify what love is: love is unalterable, unbending, and steadfast. Love is rooted, strong, and "unfoolish."