In the letter to the Ephesians 4:26, 27 it says, that we should not give the enemy an opportunity. What that means, is that any time we let our anger take the best of us, we open the door to the enemy. That is because, the anger of man, does not do the righteousness which God requires from us, as it says in the letter of James.
In Revelation 3:20, Jesus said that he knocks on the door, and whoever opens, he will come and have dinner with that person.
We have the choice which door to open daily in our lives, the one where the enemy comes, or the one through which Jesus comes. It all boils down to our own choices every day.
Every time we do the will of God, by doing daily what God requires of us, we open more and more the door for him.
And every time we do the things which God does not want us to do, we could open the door for the enemy.
It is all our choice, and opening one of the doors will bring life, but opening the other door, will bring death.
He who sows for the Spirit, will reap life and peace. He who sows for the flesh, will bring death.
It is our own responsibility to open the door for God in our life, and close the door for the enemy, on a daily basis, by carrying our cross daily, if we choose to do so.