Greater is He that is in us
Ye are of God, little children, and have overcome them: because greater is he that is in you, than he that is in the world. 1 John 4:4
The call to overcome the world, to refuse to bend to its demands, to not believe its lies, to fail to fall to its temptations, is a call for the perseverance of the saints in faith. It is important that we understand how necessary this is, for those who go out from the church back into the world only prove that they never were saved to begin with (cf. 1 Jn. 2:19). Everyone of the promises to the Seven Churches in Rev. 2-3 all hinge on the believer overcoming the world.
And yet when we understand just how frail we are spiritually and vulnerable to the wiles of the devil, the demand for perseverance can seem overwhelming, even harsh. We cry out with the hymn-writer: "Prone to wander, Lord, I feel it! Prone to leave the God I love!"
But, my friend, you need to remember in that anxious moment that the strength and power to overcome doesn't come from you, and never has: it comes from God who strengthens you with grace in Jesus Christ through the might of the Spirit of God. Why does the believer overcome the world? Not because they are wiser or smarter or stronger than others, but because "greater is he that is in you, than he that is in the world." Dear saint, take courage this day, for the Lord will never forsake his people and will ever be for you an everlasting bulwark against all enemies both within and without.