This statement was made to the Corinthians bring Paul's letter about forgiveness. He was telling them to be watchful.
Everyone who is or ever was alive, had to deal with the devil every day. You either fought him, or follow him.
He is such a master of illusions and other lies that many people don't even realize they are following him. He makes sin look harmless. He helps people rationalize sins in such a way that they think it is reasonable and good.
If you try not to sin, he tries to create doubt in your mind as to whether it really is sin or not. The Bible calls him the father of lies for a reason. He even puts a spin on the Word of God, so if you don't know the Word, you lose. He even tried that one with Jesus.
James 4:7, therefore submit to God. Resist the devil and he will flee from you. There are many verses about casting satan out. Jesus said so, so it is true.
There are however a couple of problems connected with that idea. People are not aware of fighting satan in Jesus name, or they just say the words as though they were magic. They usually say that in fear or doubt. Either way they keep doing it without results.
If you are standing on the Word, and trusting in Jesus, you will be successful. Years ago I had a neighbor who had three small girls. The girls would get into various sorts of mischief at home or while playing outside, and their mother would yell at them. Well the girls ignored her, no matter how many times or how loud the mother yelled. They knew their mother was just noise.
To get satan away from you, is not that difficult. Trust in the name of Jesus and the power of the Holy Spirit. Remember one other important thing. Since satan is a liar, have you considered the fact that the opposite must be true?
Just for example. You pray for something, and satan says it won't happen. Just say, thank you satan for confirming the answer to my prayer. Now in Jesus name, get lost. Have a very blessed day. Praise the Lord!
Remember Jesus Loves You
Prayer of Salvation
Lord Jesus, I thank you for what you did on the cross for me. Your blood washed away all my sins, by your stripes I was healed, your death and resurrection brought me salvation. Please forgive my sins, and come into my heart as my personal Savior.
Thank You Lord