James 5:12

But above all things, my brethren, do not swear, either by Heaven or by the earth, or with any other oath. Let your 'yes' be simply 'yes,' and your 'no' be simply 'no;' that you may not come under condemnation.

Matthew 5:33-37

"Again, you have heard that it was said to the ancients, 'Thou shalt not swear falsely, but shalt perform thy vows to the Lord.'

Matthew 23:16-22

"Alas for you, you blind guides, who say, "'Whoever swears by the Sanctuary it is nothing; but whoever swears by the gold of the Sanctuary, is bound by the oath.'

1 Corinthians 11:34

If any one is hungry, let him eat at home; so that your coming together may not lead to judgement. The other matters I will deal with whenever I come.

2 Corinthians 1:17-20

Did I display any vacillation or caprice in this? Or the purposes which I form--do I form them on worldly principles, now crying "Yes, yes," and now "No, no"?

James 3:1-2

Do not be eager, my brethren, for many among you to become teachers; for you know that we teachers shall undergo severer judgement.

1 Peter 4:8

Above all continue to love one another fervently, for love throws a veil over a multitude of faults.

3 John 1:2

My dear friend, I pray that you may in all respects prosper and enjoy good health, just as your soul already prospers.

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
Above all continue to love one another fervently, for love throws a veil over a multitude of faults.
3 John 1:2
My dear friend, I pray that you may in all respects prosper and enjoy good health, just as your soul already prospers.

Swear not

Matthew 5:33
"Again, you have heard that it was said to the ancients, 'Thou shalt not swear falsely, but shalt perform thy vows to the Lord.'
Matthew 23:16
"Alas for you, you blind guides, who say, "'Whoever swears by the Sanctuary it is nothing; but whoever swears by the gold of the Sanctuary, is bound by the oath.'

But

2 Corinthians 1:17
Did I display any vacillation or caprice in this? Or the purposes which I form--do I form them on worldly principles, now crying "Yes, yes," and now "No, no"?

Lest

James 3:1
Do not be eager, my brethren, for many among you to become teachers; for you know that we teachers shall undergo severer judgement.
1 Corinthians 11:34
If any one is hungry, let him eat at home; so that your coming together may not lead to judgement. The other matters I will deal with whenever I come.