[1 Jn. 5:19.] “And we know that we are of God, and the whole world lieth in wickedness”
“In the evil one”
Saint Leo the Great:
“We know indeed, as the Apostle John says, that ‘the whole world lieth in the evil one,’ and that by the stratagems of the devil and his angels numberless attempts are made either to frighten man in his struggle upwards by adversity or to spoil him by prosperity. But ‘greater is He that is in us, than he that is against us [cf. 1 Jn. 4:4],’ and they who have peace with God and are always saying to the Father with their whole hearts ‘Thy will be done [Mt. 6:10]’ can be overcome in no battles, can be hurt by no assaults. For accusing ourselves in our confessions and refusing the spirit’s consent to our fleshly lusts, we stir up against us the enmity of him who is the author of sin, but secure a peace with God that nothing can destroy, by accepting His gracious service, in order that we may not only surrender ourselves in obedience to our King but also be united to Him by our free will. For if we are like-minded, if we wish what He wishes, and disapprove what He disapproves, He will finish all our wars for us, He Who gave the will, will also give the power: so that we may be fellow workers in His works, and with the exultation of faith may utter that prophetic song, ‘The Lord is my light and my savior; whom then shall I fear? The Lord is the defender of my life; of whom then shall I be afraid [Ps. 26(27):1]?’”
~[“Sermon XXVI, On the Feast of the Nativity,” VI, § IV, in Nicene, 2nd Ser., XII:138.]
St. Cyril of Jerusalem:
4. If any man attempt to speak of God, let him first describe the bounds of the earth. Thou dwellest on the earth, and the limit of this earth which is thy dwelling thou knowest not: how then shalt thou be able to form a worthy thought of its Creator? Thou be-boldest the stars, but their Maker thou beholdest not: count these which are visible, and then describe Him who is invisible, Who telleth the number of the stars, and calleth them all by their names. Violent rains lately came pouring down upon us, and nearly destroyed us: number the drops in this city alone: nay, I say not in the city, but number the drops on thine own house for one single hour, if thou canst: but thou canst not. Learn then thine own weakness; learn from this instance the mightiness of God: for He hath numbered the drops of rain, which have been poured down on all the earth, not only now but in all time. The sun is a work of God, which, great though it be, is but a spot in comparison with the whole heaven; first gaze steadfastly upon the sun, and then curiously scan the Lord of the sun. Seek not the things that are too deep for thee, neither search out the things that are above thy strength: what is commanded thee, think thereupon.
~[NPNF, VOL 7, LECTURE 6, CONCERNING THE UNITY OF GOD ON THE ARTICLE, I BELIEVE IN ONE GOD. ALSO CONCERNING HERESIES.]