This ought to be understood in the plural.
The man you describe does not sound like a bad sort. The truth is, he may be doing more with the grace he has been given than many of us, for didn’t the Lord include this in his description of the Last Judgement: Then the righteous will answer him and say, 'Lord, when did we see you hungry and feed you, or thirsty and give you drink? When did we see you a stranger and welcome you, or naked and clothe you? When did we see you ill or in prison, and visit you?’ Matt. 25:37-39 Obviously, it is possible to please the Lord without specifically setting out to do that.
In the meantime, however, realize that it is no piece of cake for an atheist to be married to a devout Catholic, either. This sexual issue–which to his credit, he is willing to make a sacrifice for in order to satisfy your beliefs, not his own–is not going to be the last issue. What happens when he is there to watch you teach your children the faith? He will be confronted with the choice of biting his tongue or pretending beliefs he does not have, or else he will feel duty bound to tell the truth and teach your children what he honestly thinks is the truth: that even though it is in the best nature of humans to be caring and mutually willing to make sacrifices for each other out of love, God doesn’t exist and neither does most of what their mother is teaching them.
Do you want that for him? Do you want that for your children? It is a hard life. Are you willing to make sacrifices so that your husband will come to the faith, which will be your task? It is possible, but consider the great love Servant of God Elisabeth Leseur had for her husband. Archbishop Fulton Sheen tells how he heard of her story:
*Just at the turn of the century, there was a woman married in Paris, just a good, ordinary Catholic girl, to an atheist doctor, Dr. Felix Leseur. He attempted to break down the faith of his wife and she reacted and began studying her faith. In 1905, she was taken ill and tossed on a bed of constant pain until August 1914. When she was dying, she said to her husband, “Felix, when I am dead, you will become a Catholic and a Dominican priest.”
“Elizabeth, you know my sentiments. I’ve sworn hatred of God, I shall live in the hatred and I shall die in it.”
She repeated her words and passed away. She died in her husband’s arms at the early age of 47.
Rummaging through her papers, Felix found her will. She wrote:
“In 1905, I asked almighty God to send me sufficient sufferings to purchase your soul. On the day that I die, the price will have been paid. Greater love than this no woman has than she who lay down her life for her husband.”
Dr. Leseur, the atheist, dismissed her will as the fancies of a pious woman. He decided to write a book against Lourdes. He went down to Lourdes to write against Our Lady.
However, as he looked up into the face of the statue of Mary, he received the great gift of faith. So total, so complete was it, that he never had to go through the process of juxtaposition and say, “how will I answer this or that difficulty?”
He saw it all. At once.
The then reigning pontiff was Benedict XV. Then came World War I. Hearing of the conversion of Dr. Leseur, Pope Benedict XV sent for him. Dr. Leseur went in the company of Fr. Jon Vinnea, orator of Notre Dame. Dr. Leseur recounted his conversion and said that he wanted to become a Dominican priest. Holy Father said, “I forbid you. You must remain in the world and repair the harm which you have done.”
The Holy Father then talked to Fr. Vinnea and then again to Dr. Leseur and said:
“I revoke my decision. Whatever Fr. Vinnea tells you to do, you may do.”
In the year 1924, during Lent, I, Fulton J. Sheen, made my retreat in the Dominican monastery in Belgium. Four times each day, and 45 minutes in length, I made my retreat under the spiritual guidance of Father Felix Leseur of the Order of Preachers, Catholic Dominican priest, who told me this story.*
If you love him enough to marry him and believe that this is in God’s plan for you, then accept that it is also in God’s plan to give you the task of sacrificing for your husband’s conversion, and with no guarantee you will see fruit from that labor, either in this life or the next. Your story might not be as dramatic as that of Elisabeth and Felix LeSeur, but your story will require great sacrifice from both of you. Either discern that this is not your call, and give this man up to God’s care, or else resolve to give the work of his salvation your all and truly resolve to seek for him the best, which is to say a conversion into the faith handed down by the Apostles, which is the ordinary route to everlasting life.