Oath or Covenant
Jesus said, "Again you have heard that it was said to those of old, ‘You shall not swear falsely, but shall perform your oaths to the Lord.’ But I say to you, do not swear at all: neither by heaven, for it is God’s throne; nor by the earth, for it is His footstool; nor by Jerusalem, for it is the city of the great King.... But let your ‘Yes’ be ‘Yes,’ and your ‘No,’ ‘No.’ For whatever is more than these is from the evil one." Matthew 5:33-37
James wrote, "But above all, my brethren, do not swear, either by heaven or by earth or with any other oath. But let your 'Yes' be 'Yes,' and your 'No,' 'No,' lest you fall into judgment." James 5:12
Jesus said, “Woe to you, blind guides, who say, ‘Whoever swears by the temple, it is nothing; but whoever swears by the gold of the temple, he is obliged to perform it.’ Fools and blind! For which is greater, the gold nor the temple that sanctifies the gold? And, ‘Whoever swears by the altar, it is nothing; but whoever swears by the gift that is on it, he is obliged to perform it.’" Matthew 23:16-18
Since God's promises are always true, His oath alone is trustworthy"For when God made a promise to Abraham, because He could swear by no one greater, He swore by Himself, saying, 'Surely blessing I will bless you, and multiplying I will multiply you.' And so, after he had patiently endured, he obtained the promise. For men indeed swear by the greater, and an oath for confirmation is for them an end of all dispute. Thus God, determining to show more abundantly to the heirs of promise the immutability of His counsel, confirmed it by an oath, that by two immutable things, in which it is impossible for God to lie, we might have strong consolation, who have fled for refuge to lay hold of the hope set before us.
"This hope we have as an anchor of the soul, both sure and steadfast, yand which enters the Presence behind the veil, where the forerunner has entered for us, even Jesus, having become High Priest forever according to the order of Melchizedek." Hebrews 6:13-19
"And to whom did He swear that they would not enter His rest, but to those who did not obey? So we see that they could not enter in because of unbelief." Hebrews 3:18-19"As He spoke by the mouth of His holy prophets....
That we should be saved from our enemies and from the hand of all who hate us,
To perform the mercy promised to our fathers and to remember His holy covenant,
The oath which He swore to our father Abraham:
To grant us that we, being delivered from the hand of our enemies,
Might serve Him without fear,
In holiness and righteousness before Him all the days of our life." Luke 1:70-75See also Covenant