James 5:12

But above all, my brethren, swear not; neither by heaven, nor by the earth, nor any other oath: but let your yea be yea, and your nay nay; that ye may not fall under condemnation.

Matthew 5:33-37

Again, ye have heard, that it was said to the ancients, Thou shalt not forswear thyself, but shalt perform unto the Lord thine oaths:

Matthew 23:16-22

Wo unto you, ye blind guides, who say, If any one swear by the temple, it is nothing;

1 Corinthians 11:34

and if any one be hungry, let him eat at home, that ye may not come together to your condemnation. And as to other things, I will set them in order when I come.

2 Corinthians 1:17-20

Now when I intended this, was I chargeable with levity? or what I purpose, do I purpose from carnal motives, that with me there should be yea, yea, and then no, no?

James 3:1-2

My brethren, be not many teachers, knowing that we who are such shall pass a stricter trial than others: for in many things we all offend;

1 Peter 4:8

having above all things fervent love to each other; for love will cover a multitude of sins.

3 John 1:2

Beloved, I earnestly pray, that thou mayst prosper and be in health, as thy soul prospereth.

Treasury of Scripture Knowledge

Summary

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.

Bible References

Above

1 Peter 4:8
having above all things fervent love to each other; for love will cover a multitude of sins.
3 John 1:2
Beloved, I earnestly pray, that thou mayst prosper and be in health, as thy soul prospereth.

Swear not

Matthew 5:33
Again, ye have heard, that it was said to the ancients, Thou shalt not forswear thyself, but shalt perform unto the Lord thine oaths:
Matthew 23:16
Wo unto you, ye blind guides, who say, If any one swear by the temple, it is nothing;

But

2 Corinthians 1:17
Now when I intended this, was I chargeable with levity? or what I purpose, do I purpose from carnal motives, that with me there should be yea, yea, and then no, no?

Lest

James 3:1
My brethren, be not many teachers, knowing that we who are such shall pass a stricter trial than others: for in many things we all offend;
1 Corinthians 11:34
and if any one be hungry, let him eat at home, that ye may not come together to your condemnation. And as to other things, I will set them in order when I come.