Simply replace the unfilled areas such as "__" and "_[date]_" with your information.
Dear [name of spouse]
I am so thankful that God brought you into my life, and I pray each and every day that God will keep you strong and with me. You are everything a wife could want: You are a strong Christian man that provides our family with direction and leadership. I know that God always knows what he is doing in our lives, and he certainly knew what he was doing when he brought you and me together. I love you so much, and just wanted to let you know how grateful I am for everything you do for all of us.