Be sober, be vigilant; because your adversary the devil, as a roaring lion, walketh about, seeking whom he may devour.@1 Peter 5:8

George A. Griswold, in Sunday School Hymns No. 2 (New York: Tullar-Meredith, 1912), page 112 (🔊 pdf nwc).

Be thou watchful, O my soul!
Let not the evil powers control!
O never doff thine armor,
O never sheathe thy sword!
Satan’s zeal will never cool
Christ’s ransomed ones to grasp and rule;
Thou art not for a moment safe
Apart from thy Lord.

Refrain

Be sober! be vigilant! Stand on thy guard;
Evil is on thy track, pressing thee hard;
However smooth appearance be,
Suspect the lurking enemy!
O stand on thy guard!
Stand on thy guard!

Watch against the hidden host
Who in the Prince of Darkness boast!
Not solely with the human
Thy spirit must contend;
Roaring as a lion loud
Or with an angel’s guise endowed,
The host of hell will tempt thee sore,
So watch to the end.

Refrain

Watch and pray, the Savior said,
Lest in temptation you be led!
And Jesus watcheth with you
As on your guard you stand.
Vainly you observe the foe
Unless your Lord observe them, too,
And shield you from the fiery darts
Hurled forth from their hand.

Refrain