Here are some passages that use this term:
Psalms 7:9 Oh let the wickedness of the wicked come to an end; but establish the just: for the righteous God trieth the hearts and reins.
Psalms 26:2 Examine me, O LORD, and prove me; try my reins and my heart.
Psalms 16:7 I will bless the LORD, who hath given me counsel: my reins also instruct me in the night seasons.
Jeremiah 11:20 But, O LORD of hosts, that judgest righteously, that triest the reins and the heart, let me see thy vengeance on them: for unto thee have I revealed my cause.
Jeremiah 17:10 I the LORD search the heart, I try the reins, even to give every man according to his ways, and according to the fruit of his doings.
Jeremiah 20:12 But, O LORD of hosts, that triest the righteous, and seest the reins and the heart, let me see thy vengeance on them: for unto thee have I opened my cause.
Revelation 2:23 And I will kill her children with death; and all the churches shall know that I am he which searcheth the reins and hearts: and I will give unto every one of you according to your works.
Truly the Lord knows our hearts, He knows what drives us, what compels us, what makes us tick! He knows whether it is sin or righteousness that drives us, whether it is a desire to please Him or please ourselves that is our main motivation.
This is an Old Testament passage regarding the Messiah, the Lord Jesus Christ. Notice what guides Him:
Isaiah 11:5 And righteousness shall be the girdle of his loins, and faithfulness the girdle of his reins.
What is driving us? Is it thoughts of the Lord that possess us, thoughts of His Word that drive us, is it a desire to be close to our Heavenly Father? Or is it a desire to be rebellious, to go our own way, to put on a show with no real desire or heart for God behind it? What's driving you?
Psalms 139:13 For thou hast possessed my reins: thou hast covered me in my mother's womb.
Proverbs 23:16 Yea, my reins shall rejoice, when thy lips speak right things.
Jeremiah 12:2 Thou hast planted them, yea, they have taken root: they grow, yea, they bring forth fruit: thou art near in their mouth, and far from their reins.
Now, I am going to go somewhere else in these thoughts that seem unrelated, but in actual fact is quite related.
Do I serve the Lord out of duty or out of love? What's my motivation? What's driving me? How about you? What's driving you? (My thoughts here build a bit upon my blog from several days ago: Love - The Motivating Factor; and Love Versus Duty.)
Analysing this in my own life has been a real eye-opener. There are many times I have simply obeyed and served the Lord out of duty. I always wondered why so often I was like a leaky tire. You know the type - you get pumped up by some preaching, get all excited about doing something for the Lord (especially when you know it is incorporating or strengthening something in your life that should be there), start out good, and then eventually all the air is gone out and soon you are back to your old self. This momentary zeal never seems to last for long. I have learned that serving out of duty doesn't last!
This statement was posted in the thread where I was discussing this issue, in the context of the bondservant:
"I liken all of this to the slave who is set free and then decides that he loves his master and of his own free will decides to submit himself and become a slave again. He THEN is bound by duty that he FREELY chose because of LOVE. He loved, then he CHOSE, then he was DUTY-BOUND, all the while still loving his master."
Deuteronomy 15:12-17 And if thy brother, an Hebrew man, or an Hebrew woman, be sold unto thee, and serve thee six years; then in the seventh year thou shalt let him go free from thee. And when thou sendest him out free from thee, thou shalt not let him go away empty: Thou shalt furnish him liberally out of thy flock, and out of thy floor, and out of thy winepress: of that wherewith the LORD thy God hath blessed thee thou shalt give unto him. And thou shalt remember that thou wast a bondman in the land of Egypt, and the LORD thy God redeemed thee: therefore I command thee this thing to day. And it shall be, if he say unto thee, I will not go away from thee; because he loveth thee and thine house, because he is well with thee; Then thou shalt take an aul, and thrust it through his ear unto the door, and he shall be thy servant for ever. And also unto thy maidservant thou shalt do likewise.
This passage (and the parallel one, Exodus 21:2-6) has intrigued me since I really learned what it meant and and what it pictured several years ago: Being set free, but choosing to remain as a willing bond servant to your master - even so, it pictures the believer being set free from sin and condemnation, and choosing to remain a willing bondservant to his Heavenly Master.
What is pictured in these passages is the bondservant - a servant/slave that is set free, and who willingly gives himself in loving service back to his master. In the New Testament, every time you read the word "servant," this is what is in view - the bondservant. And this is what the following verse is referring to - in light of all the Lord has done to save us and give us the victory in Christ, it is only reasonable to give ourselves back to our Heavenly Master in loving service to Him.
Romans 12:1 I beseech you therefore, brethren, by the mercies of God, that ye present your bodies a living sacrifice, holy, acceptable unto God, which is your reasonable service.
In light of these discussions, and my prior thoughts/conclusions on this issue, I realize that I missed the boat before in some ways. It was duty that guided my reins, that drove me - and that left me lacking. Now I see that if it is love that guides my reins, I will fulfill all the obligations of duty, but the motivation will be completely different - my ability to please my Heavenly Father will be different. (See Luke 17:10) And from what I am learning and experiencing in my own life, true love for the Lord Jesus Christ doesn't run out like a leaky tire - it keeps going strong. It is what is driving me now, it is what is constraining and compelling me in my service for the Lord:
2 Corinthians 5:14 For the love of Christ constraineth us; because we thus judge, that if one died for all, then were all dead:
I am sure I have so far still to go, but I am learning.
Matthew 22:37-39 Jesus said unto him, Thou shalt love the Lord thy God with all thy heart, and with all thy soul, and with all thy mind. This is the first and great commandment. And the second is like unto it, Thou shalt love thy neighbour as thyself.
Romans 13:8 Owe no man any thing, but to love one another: for he that loveth another hath fulfilled the law.
Previously, I wasn't sure how to tie all these passages that have leaped out at me lately (remember me stating that when God gets your attention in some area, you see that truth everywhere in Scripture?), but they all fit right here:
Galatians 5:6 For in Jesus Christ neither circumcision availeth any thing, nor uncircumcision; but faith which worketh by love.
Galatians 5:13-14 For, brethren, ye have been called unto liberty; only use not liberty for an occasion to the flesh, but by love serve one another. For all the law is fulfilled in one word, even in this; Thou shalt love thy neighbour as thyself.
Ephesians 5:2 And walk in love, as Christ also hath loved us, and hath given himself for us an offering and a sacrifice to God for a sweetsmelling savour.
2 Timothy 1:7 For God hath not given us the spirit of fear; but of power, and of love, and of a sound mind.
Hm, I just found this verse while I was copying the others that have impressed me lately:
1 Thessalonians 5:8 But let us, who are of the day, be sober, putting on the breastplate of faith and love; and for an helmet, the hope of salvation.
A breastplate guards our heart - the believer's heart is to be guarded by faith (trust and reliance upon God's Word) and love.
1 John 4:17-19 Herein is our love made perfect, that we may have boldness in the day of judgment: because as he is, so are we in this world. There is no fear in love; but perfect love casteth out fear: because fear hath torment. He that feareth is not made perfect in love. We love him, because he first loved us.
I can honestly say there has been some major differences in my life when my motivation has been love - when these were the reins that guided and directed me, rather than simply duty. What's driving you?