Again, you have heard that is was said to the people long ago, "Do not break your oath, but keep the oaths you have made to the Lord." But I tell you, Do not swear at all: either by heaven, for it is God's throne; or by earth, for it is his footstool; or by Jerusalem, for it is the city of the Great King. And do not swear by your head, for you cannot make even one hair white or black. Simply let your "Yes" be "Yes" and your "No" be "No"; anything beyond this comes from the evil one. (Mathew 5:33-37)


Do not conform any longer to the patter of this world, but be transformed by the renewing of your mind. Then you will be able to test and approve what God's will is - his good, pleasing and perfect will. (Romans 12:2)