It is possible to eliminate all known religions except Christianity as possibly true based on reason alone.
God’s existence as First Cause is provable by reason alone. This is in fact the most basic definition of God.
God being love is a derivative of the truth of his infinity and the oneness of his existence with his attributes. Love demands an object, therefore, God cannot be himself without creation. This is fallacious, therefore, God must be at least two, not one, as in Father and Son, rather than Allah.
This eliminates all religions except Christianity, as no religion has a First Cause that is at least two in Person.
One may say that God can love an eternal angel as another being and maintain his nature as love, however, he could not have been that nature as love from the beginning before the creation of the universe.