Though this question is approached differently in certain non-western cultures, the highest quality of love is only manifest when freedom of choice exists. God's love is so far beyond human experience that to glimpse it we must understand human love in its highest form, then extrapolate. Divine love is reflected by human love in the biblical illustration of bride and bridegroom. Love originates in a one-sided fashion, but must be reciprocated. If it is, true love can grow totally and completely, and the persons may entrust themselves to each other.
Love is built on mutual respect and consent.
Thus absolutely free choice is a prerequisite for true love. God has chosen to give us divine love, and desires that we freely choose to love him. God does not force us to return his love, because to do so would destroy true love. Of God's own free will, he died to free us from guilt and re-establish fellowship, a costly love, and indeed truest love. The conclusion is that God has chosen to place a very high value on preserving our free choice so that true love remains possible.