Grown Children's Salvation

Please pray for my grown children. The 2 who were the most on fire growing up are now calling themselves atheist or agnostic. My daughter is engaged to a man who believes the same. Four others would say they believe in God but are not going to church or walking closely with Him. Pray for my youngest 16, who has a strong faith did the others...that he would not turn from God. Thank you for your prayers!