Gird Up the Loins of Your Mind
Wherefore gird up the loins of your mind, be sober, and hope to the end for the grace that is to be brought unto you at the revelation of Jesus Christ; 
(1 Peter 1:13)
"Gird up thy loins" is an Old Covenant phrase that means get dressed and prepare to move. When we read in 2 Kings 4:29, we see that Elisha gave his servant Gehazi an instruction to get up and go somewhere. 

In the instance as described below it is an instruction to born again Christians to get their minds out of neutral, to stop listening passively to the dissertations of others, but to find out what it is that the Lord requires of them. 
 
To find out more let's read the rest of the passage:
Wherefore gird up the loins of your mind, be sober, and hope to the end for the grace that is to be brought unto you at the revelation of Jesus Christ; 14 As obedient children, not fashioning yourselves according to the former lusts in your ignorance: 15 But as he which hath called you is holy, so be ye holy in all manner of conversation; 16 Because it is written, Be ye holy; for I am holy. 17 And if ye call on the Father, who without respect of persons judgeth according to every man's work, pass the time of your sojourning here in fear: 18 Forasmuch as ye know that ye were not redeemed with corruptible things, as silver and gold, from your vain conversation received by tradition from your fathers; 19 But with the precious blood of Christ, as of a lamb without blemish and without spot: 20 Who verily was foreordained before the foundation of the world, but was manifest in these last times for you, 21 Who by him do believe in God, that raised him up from the dead, and gave him glory; that your faith and hope might be in God. 22 Seeing ye have purified your souls in obeying the truth through the Spirit unto unfeigned love of the brethren, see that ye love one another with a pure heart fervently: 23 Being born again, not of corruptible seed, but of incorruptible, by the word of God, which liveth and abideth for ever. 24 For all flesh is as grass, and all the glory of man as the flower of grass. The grass withereth, and the flower thereof falleth away: 25 But the word of the Lord endureth for ever. And this is the word which by the gospel is preached unto you. 
(1 Peter 1:13-25)
Firstly here is confirmation that once born again always born again is a fallacy, as we saw in the study of the Blood Covenant. As we see "pass the time of your sojourning here in fear" can only mean one thing. 

This verse also makes it very clear that our sojourning (stopover) here, our stay on planet earth in our worldly bodies, is just a passing phase in the everlasting life of our souls, which is the real us. 
We also see that we were redeemed (repurchased) by the precious blood of Jesus Christ. This gives us the hope, the potential, to become the sons of God one day. 
Glory to you Lord Jesus for this priceless gift. 
But as many as received him, to them gave he power to become the sons of God, even to them that believe on his name: 
(John 1:12)
We have the power to become the sons of God, we don't have it now as is preached in some denominations. 

Before being born again we were without this hope: 
That at that time ye were without Christ, being aliens from the commonwealth of Israel, and strangers from the covenants of promise, having no hope, and without God in the world: 
(Ephesians 2:12)

This is confirmed in the main passage above if read carefully. 
 
Going back to verse seventeen,
And if ye call on the Father, who without respect of persons judgeth according to every man's work, pass the time of your sojourning here in fear: 
(1 Peter 1:17)
we see that there is no favouritism with God; also we will be judged according to our work. If there is no work, and this includes charity, judgement will be unfavourable. Most importantly, it is not what we believe is good work, but what God knows is good work. 

This is confirmed by that eye opening passage of scripture that is so often misquoted or twisted by the workers of iniquity: 
That in the ages to come he might shew the exceeding riches of his grace in his kindness toward us through Christ Jesus. For by grace are ye saved through faith; and that not of yourselves: it is the gift of God: Not of works, lest any man should boast. For we are his workmanship, created in Christ Jesus unto good works, which God hath before ordained that we should walk in them. 
(Ephesians 2:7-10)
 
Finally it is confirmed in verses twenty three and twenty five that the word of the Lord, the Bible, is a living word and further that it lives forever. 

This means that just as our souls live forever, so does the word. It will always be with us, before our eyes, whether we are in heaven with the Godhead, or in the lake of fire with Satan and his cronies. 
 
That the trial of your faith, being much more precious than of gold that perisheth, though it be tried with fire, might be found unto praise and honour and glory at the appearing of Jesus Christ: 
(1 Peter 1:7)