The closer we are to God in prayer, love and obedience the harder the devil works to lead us astray. There is no point in him tempting those who do not believe.
The devil knows us very well; he knows our weaknesses and our fears. He plays on those fears and will turn those thoughts into worries and severe anxieties about the future, about our loved ones, about health or financial issues, or anything else that would take our focus away from God.
We need to recognise these temptations immediately as they manifest themselves. The more our lives are centred on Christ the easier this reflex reaction will become; and at the very first instant we turn away every shred of anxiety over to Jesus by praying repeatedly, "over to you, Lord, help me."
We consciously, and as forcibly as we possibly can, we exclude from our mind every anxiety and evil-inspired thought and hand it over to God's influence. And with trust and hope see Him restore peace of mind and optimism into our lives.