Before Jesus' Incarnation, divorce was necessary. Laws regulating divorce even appear in the Bible (see Dt 24:1-4). Before Jesus saved us, polygamy, not monogamy, was widely practiced. Before Jesus, single persons were usually considered cursed. Before Jesus, our understanding of love, marriage, sexual relations, the dignity of the human person, and vocations was very incomplete and perverted.
After we accept Jesus as Lord of our lives, we have the grace to develop great marriages of total self-giving. This usually results in large, happy, and beautiful families. In Christ, the divorced do not live lives of serial polygamy but lives of heroic faithfulness. They love unilaterally and unconditionally, as Jesus loves. Also, after Jesus has saved us, we see those who are single for the Lord as prophetic signs of our future lives in the kingdom of heaven (Mt 19:12; Lk 20:34ff).
Look at your vocation to the married or single life. Is your marriage or divorce B.C. or A.D.? Are you decidedly and delightfully single? Or are you merely "unmarried?" In Christ, all relationships and vocations are radically transformed. "This means that if anyone is in Christ, he is a new creation. The old order has passed away; now all is new!" (2 Cor 5:17)