The answer to your question is an unqualified yes. God clearly declares in his Word that the only reason he recognizes for a marriage to come to an end (other than death, of course) is unfaithfulness. Such unfaithfulness may take the form of adultery (Matthew and Mark) or malicious abandonment (1 Corinthians), but the fact remains that it is unfaithfulness that breaks a marriage. God hates divorce and even sets the pattern for our faithfulness by remaining faithful to us, despite the sad truth that we have prostituted ourselves to sin. I urge the two of you to seek solid biblical counseling to help you through your issues, to beseech the LORD in prayer, and to seek in all you do to carry out the LORD'S will for your lives.