This watchman received in spirit that this is the sign: put on your full armor of God.
This means: having the full alertness and consciousness of the mighty presence of God and His Word, Spirit-filled and Spirit-led at all times. Listening to audio Bible and reading at the same time is one way of keeping focused on God and matters of God, just as our Lord and Savior Jesus has commanded. (John 15:7 If you abide in Me, and My words abide in you, ask whatever you wish, and it will be done for you.)
Ephesians 6 New American Standard Bible (NASB)
10 Finally, be strong in the Lord and in the strength of His might. 11 Put on the full armor of God, so that you will be able to stand firm against the schemes of the devil. 12 For our struggle is not against flesh and blood, but against the rulers, against the powers, against the world forces of this darkness, against the spiritual forces of wickedness in the heavenly places. 13 Therefore, take up the full armor of God, so that you will be able to resist in the evil day, and having done everything, to stand firm. 14 Stand firm therefore, having girded your loins with truth, and having put on the breastplate of righteousness, 15 and having shod your feet with the preparation of the gospel of peace; 16 in addition to all, taking up the shield of faith with which you will be able to extinguish all the flaming arrows of the evil one. 17 And take the helmet of salvation, and the sword of the Spirit, which is the word of God.
18 With all prayer and petition pray at all times in the Spirit, and with this in view, be on the alert with all perseverance and petition for all the saints, 19 and pray on my behalf, that utterance may be given to me in the opening of my mouth, to make known with boldness the mystery of the gospel, 20 for which I am an ambassador in chains; that in proclaiming it I may speak boldly, as I ought to speak…
23 Peace be to the brethren, and love with faith, from God the Father and the Lord Jesus Christ. 24 Grace be with all those who love our Lord Jesus Christ with incorruptible love.
Romans 13 New American Standard Bible (NASB)
11 Do this, knowing the time, that it is already the hour for you to awaken from sleep; for now salvation is nearer to us than when we believed. 12 The night is almost gone, and the day is near. Therefore let us lay aside the deeds of darkness and put on the armor of light. 13 Let us behave properly as in the day, not in carousing and drunkenness, not in sexual promiscuity and sensuality, not in strife and jealousy. 14 But put on the Lord Jesus Christ, and make no provision for the flesh in regard to its lusts.
Luke 11 New American Standard Bible (NASB)
20 But if I cast out demons by the finger of God, then the kingdom of God has come upon you. 21 When a strong man, fully armed, guards his own house, his possessions are undisturbed. 22 But when someone stronger than he attacks him and overpowers him, he takes away from him all his armor on which he had relied and distributes his plunder. 23 He who is not with Me is against Me; and he who does not gather with Me, scatters.
1 John 4:4 New American Standard Bible (NASB)
4 You are from God, little children, and have overcome them; because greater is He who is in you than he who is in the world.