The anger of lovers renews the strength of love.

A quarrel between two people who care about each other is often a sign that something mattered enough to be defended. Where there is no friction at all, it can mean indifference rather than harmony. The strength comes from the repair afterwards rather than from the argument, since what is learned is that the relationship survives being tested.

That is not a case for picking fights. It is a case for not treating every disagreement as damage. If something is unresolved between you and somebody close, raise it while it is still small, and give as much attention to the making up as to the point you wanted to make.