What is love if it isn't reciprocated? It falls into nothing. If one does not reciprocate God's love, he is no better than a heathen.
We were created to Love God that is true, and without the continued relationship of being Loved and loving in return it eventually falls into nothing, you are right in this.
But the very nature of Love is that it is only giving without the expectation of receiving back. The one who gives of His life in spite of not receiving anything back from those He died for Loves most greatly of all.
Jesus died for the sin of the world, while we were His enemies but only a small proportion of us even acknowledge the sacrifice, far less return His life in kind.
If a wife does not reciprocate a man's love, she has put asunder what God has joined. How many marriages last is love isn't present with both parties?
Did you not know God gave His beloved, Israel, a bill of divorcement? Do you know why?
Jeremiah 3:8
And I saw, when, for this very cause that backsliding Israel had committed adultery, I had put her away and given her a bill of divorcement, yet treacherous Judah her sister feared not; but she also went and played the harlot.
Israel did not return the love God had given them. They backslid and committed adultery.
And what of Gods Love demonstrated through prophetic action of Hosea? In the face of his prostitute wife, even though she was faithless, he received her back and loved her over and over again.
If your wife committed adultery, do you think she loved you and there was a godly union between the two of you?
At one time I would have wished I could agree with you, it would have made the broken relationship I experienced at the hands of an unloving woman a lot easier to bear, I could have thrown her away a lot earlier before I failed.
But it was God who time and time again urged me to live from the Cross and Love her. It was my choice to do so in imitation of Him but it was in imitation of His Love for us.
The Godly union between a man and a woman has to do with covenant, a mutually unilateral covenant that is analogous to the union that exists within the God head.
The conditions of the marriage covenant are various in different cultures and so perhaps in your culture the conditions make provision for annulment in the case of non-reciprocated Love.
But in my culture, the culture of Jesus, annulment is only permitted in the case of adultery, and this not so much because adultery destroys the conditions of the covenant (which is unilateral) but because the hardness of heart that leads to adultery is such that it is probably better for both parties if the relationship is allowed to dissolve, if one or both parties wish it to do so.
Jesus replied, “Moses permitted you to divorce your wives because your hearts were hard. But it was not this way from the beginning. I tell you that anyone who divorces his wife, except for sexual immorality, and marries another woman commits adultery.” (Matthew 19)