The Lovers indicates both the most powerful of unions and the most of challenging conflicts humans must face. All of the elements are there for the perfect union. The Lovers represent all powerful unions in general, and the elements that create/sustain them.
The problem The Lovers face is temptation and the decision to act morally or abandon their ethics to take advantage of other opportunities that would be defined as transgressions.
The Lovers' influence is increased when The Empress is among your personal cards. Having The Hierophant or The Hermit in your personal cards may diminish the influence of the Lovers.