The idiom, "The devil is in the detail" refers to a catch or mysterious element hidden in the details, meaning that something might seem simple at a first look but will take more time and effort to complete than expected and derives from the earlier phrase, "God is in the detail" expressing the idea that whatever one does should be done thoroughly; i.e. details are important. Wikipedia
How someone got from "God is in the detail" to "The Devil is in the detail" is beyond me. Apparently, someone was looking at life as a glass half empty.
Psalm 37:23 The steps of a man are established by the Lord, when he delights in his way;
As followers of Jesus, we should believe that our God is in the details of our life. But as the Psalmist says, that will only happen when we delight ourselves in His ways. If we don't, then we invite Satan into the details of our lives.
Song of Solomon 2:15 warns us that it is the little foxes that spoil the vines. Or in other words, the things that we do not pay attention to are the very things that can ruin us. The details. So what details are you not paying attention to in your marriage? Your family? Your job or your life? It is those things that you need to give over to God and ask Him, "What should I do about these things?"
PRAY: Dear Jesus, help me to pay attention to what is going on in my life today. Then give me wisdom on how to deal with them. AMEN.