But above all things, my brethren, swear not, neither by heaven, neither by the earth, neither by any other oath: but let your yea be yea; and your nay, nay; lest ye fall into condemnation.Matthew 5:33-37
Again, ye have heard that it hath been said by them of old time, Thou shalt not forswear thyself, but shalt perform unto the Lord thine oaths:But above all things, James is stressing the importance of not swearing, just as Jesus told us, James is reemphasizing the importance of watching what we say, to speak with truth, the first yes is the promise and the second yes is the action. You do not need an oath to speak the truth, but only to say what you will do and do what you say.
But I say unto you, Swear not at all; neither by heaven; for it is God's throne:
Nor by the earth; for it is his footstool: neither by Jerusalem; for it is the city of the great King.
Neither shalt thou swear by thy head, because thou canst not make one hair white or black.
But let your communication be, Yea, yea; Nay, nay: for whatsoever is more than these cometh of evil.
If a man vow a vow unto the LORD, or swear an oath to bind his soul with a bond; he shall not break his word, he shall do according to all that proceedeth out of his mouth.Deuteronomy 23:21-23
When thou shalt vow a vow unto the LORD thy God, thou shalt not slack to pay it: for the LORD thy God will surely require it of thee; and it would be sin in thee.Our words have weight, and we should use them carefully. God tells us that if we make an oath, a promise, and we fail to keep it, we sin.
But if thou shalt forbear to vow, it shall be no sin in thee.
That which is gone out of thy lips thou shalt keep and perform; even a freewill offering, according as thou hast vowed unto the LORD thy God, which thou hast promised with thy mouth.
Is any among you afflicted? let him pray. Is any merry? let him sing psalms.Ephesians 5:19
Speaking to yourselves in psalms and hymns and spiritual songs, singing and making melody in your heart to the Lord;Colossians 3:16
Let the word of Christ dwell in you richly in all wisdom; teaching and admonishing one another in psalms and hymns and spiritual songs, singing with grace in your hearts to the Lord.In the Christian's life look at the importance of prayer and praise, when we are afflicted, we need to pray. When we are merry, prosperous, blessed, we should give praise and thanksgiving. We should be in constant communication with God through prayer and praise.
Is any sick among you? let him call for the elders of the church; and let them pray over him, anointing him with oil in the name of the Lord:Matthew 18:19
And the prayer of faith shall save the sick, and the Lord shall raise him up; and if he have committed sins, they shall be forgiven him.
Again I say unto you, That if two of you shall agree on earth as touching any thing that they shall ask, it shall be done for them of my Father which is in heaven.Matthew 21:22
And all things, whatsoever ye shall ask in prayer, believing, ye shall receive.John 14:13-14
And whatsoever ye shall ask in my name, that will I do, that the Father may be glorified in the Son.These are great promises, if we are sick, pray. Who should pray? The elders of the church, and pray with faith in the name of the Lord.
If ye shall ask any thing in my name, I will do it.
Why do you think James is having the elders pray?
I believe it has to do with wisdom, with maturity, the prayer of faith, who better than the elders of the church to understand the importance of faith based prayer. To not pray amiss, to pray towards the glory of God.
In studying this a bit deeper, we can take "sick" to mean physical ailment, or spiritual ailment, and the anointing with oil as applying a balm or salve to physical wounds or ailments, or a metaphorical anointing of the spiritually ill or weak with correction, encouragement, and strengthening of Godly fellowship.
Either way, it seems the importance is on mature, righteous, faith based prayer, all done in the name of the Lord, for the glory of God, to bring about the healing, and strengthening of those that are "sick" or in need.
But let him ask in faith, nothing wavering. For he that wavereth is like a wave of the sea driven with the wind and tossed.James 4:3
Ye ask, and receive not, because ye ask amiss, that ye may consume it upon your lusts.Proper and effectual prayer, in Jesus name, with faith to the glorification of God will do great things!
Confess your faults one to another, and pray one for another, that ye may be healed. The effectual fervent prayer of a righteous man availeth much.Confessing our faults to one another, that can be hard, we all have faults, we all have struggles, and the confession of those faults, the asking of forgiveness, the fellowship with our brethren, heals, and strengthens us.
Iron sharpeneth iron; so a man sharpeneth the countenance of his friend.Colossians 3:16
Let the word of Christ dwell in you richly in all wisdom; teaching and admonishing one another in psalms and hymns and spiritual songs, singing with grace in your hearts to the Lord.Hebrews 10:24-25
And let us consider one another to provoke unto love and to good works:Acts 2:42
Not forsaking the assembling of ourselves together, as the manner of some is; but exhorting one another: and so much the more, as ye see the day approaching.
And they continued stedfastly in the apostles' doctrine and fellowship, and in breaking of bread, and in prayers.Acts 6:4
But we will give ourselves continually to prayer, and to the ministry of the word.You see this fellowship, confession, ministry, prayer, living in the doctrine and ministry of the word is the only way for Christians to grow, and mature. This is how Christians build a strong church, a strong walk with God. This is how we prepare ourselves to be instruments used by God for His glory and purpose.
James finishes up the verse stating that the effectual, fervent prayer of a righteous man availeth much, that means it is useful, helpful, advantageous, and will produce or result in a benefit or advantage.
Elias was a man subject to like passions as we are, and he prayed earnestly that it might not rain: and it rained not on the earth by the space of three years and six months.James now gives us an example of the power of prayer, but look at this, Elias (Elijah), was a man just like us. Subject to like passions as we are. He was human and depended on God just as we do.
And he prayed again, and the heaven gave rain, and the earth brought forth her fruit.
And saying, Sirs, why do ye these things? We also are men of like passions with you, and preach unto you that ye should turn from these vanities unto the living God, which made heaven, and earth, and the sea, and all things that are therein:Acts 10:26
But Peter took him up, saying, Stand up; I myself also am a man.Here we have Barnabas, Paul, and Peter declaring they are just like us, human flesh and blood, dependent on God, just like we are.
Elijah prayed earnestly, with faith, for the glory of God, so that we might know who God is, and it did not rain for three and half years...
Then Elijah prayed again, and heaven gave rain and the earth brought forth her fruit. All for the glory of God, so that we might know who God is.
Brethren, if any of you do err from the truth, and one convert him;Christians should be working to perfect their walk with God, having fellowship with our brothers in Christ, studying God's Word, so that we do not err from the truth. If we have brothers that err, we should work to convert them back to the truth.
Let him know, that he which converteth the sinner from the error of his way shall save a soul from death, and shall hide a multitude of sins.
But I have prayed for thee, that thy faith fail not: and when thou art converted, strengthen thy brethren.Ephesians 2:10
For we are his workmanship, created in Christ Jesus unto good works, which God hath before ordained that we should walk in them.Acts 26:18
To open their eyes, and to turn them from darkness to light, and from the power of Satan unto God, that they may receive forgiveness of sins, and inheritance among them which are sanctified by faith that is in me.We are to be soul winners, ambassadors for Christ, to reconcile the world to God. James is stressing that importance, to correct, strengthen, and sharpen each other, to pray, to praise, to draw nigh God, and how we should behave as Christians.