There is a real way in which Satan is active in our lives even today.
1 Pet. 5:8-9—Be sober, be vigilant; because your adversary the devil, as a roaring lion, walketh about, seeking whom he may devour: 9 Whom resist stedfast in the faith, knowing that the same afflictions are accomplished in your brethren that are in the world.
We are required to stedfastly resist him – in the faith. We need to fully know where he is and what he is doing so we are able to resist him.