Jesus told his disciples:

33 “Again you have heard that it was said to them of old time, ‘You shall not make false vows, but shall perform to the Lord your vows,’ 34 but I tell you, don’t swear at all: neither by heaven, for it is the throne of God; 35 nor by the earth, for it is the footstool of his feet; nor by Jerusalem, for it is the city of the great King. 36 Neither shall you swear by your head, for you can’t make one hair white or black. 37 But let your ‘Yes’ be ‘Yes’ and your ‘No’ be ‘No.’ Whatever is more than these is of the evil one."

Matthew 5:27-32 - World English Bible

Obviously, the Third Commandment prohibits taking loose oaths. Too often people use the phrase "I swear to God, that..." as a means to prop up an assertion. But a closer look at this passage revealed that the question of swearing without thinking was a side issue.

Jesus addressed the entire question of making any promise to God. This was controversial at the time and still is. In Acts 18:18, St. Paul implicitly swore an oath to the Lord when he took a Nazirite vow (cut his hair). Yet, James 5:12 stated: "But above all things, my brothers, don’t swear— not by heaven, or by the earth, or by any other oath; but let your “yes” be “yes”, and your “no”, “no”; so that you don’t fall into hypocrisy." The Torah did not prohibit solemn oaths to be sworn, but regulated them (Deuteronomy 23:21-23). However, to keep the faithful from breaking the Law, Jesus commanded his followers from making any oath, without any "work-arounds" (swearing by heaven or God's throne or the earth or Jerusalem or even by one's own self), for everything came from God. He wanted his followers to give a straight answer and mean it.

Should we make any deals with God, any promises we need to keep? I've heard too many stories of conversion based upon promises to the Lord to give a hard answer. But, we should keep the Lord's words in mind when we are tempted to make a vow. Such a promise must be taken most seriously.

Pray before you promise anything to God or another human being.