Jeremiah 42:5-6 New King James Version
5 So they said to Jeremiah, “Let the Lord be a true and faithful witness between us, if we do not do according to everything which the Lord your God sends us by you. 6 Whether it is pleasing or displeasing, we will obey the voice of the Lord our God to whom we send you, that it may be well with us when we obey the voice of the Lord our God.”

The issue with calling on G-d to witness a pact is that since the heart of man is inclined to sin, evil, treachery, and disobedience, is that we are admonished not to make a vow to Him that we are not willing to keep.

Ecclesiastes 5:5  Better not to vow than to vow and not pay.

The Israelites were walking by sight, and forgot that time and again when they beseeched the Lord and turned from their sin, they were forgiven and restored.

The Father , however, was not above culling the sinful from their midst. They wanted to return to Egypt where they believed the conditions of bondage was better for them than the sovereignty of G-d. On the pretense of being obedient, they turned to Jeremiah to bring them the word of the Lord, but they also vowed to do whatever the Lord said, even if it was displeasing.

The prophet fulfilled his part, but here’s what the people responded:

43 Now it happened, when Jeremiah had stopped speaking to all the people all the words of the Lord their God, for which the Lord their God had sent him to them, all these words, 2 that Azariah the son of Hoshaiah, Johanan the son of Kareah, and all the proud men spoke, saying to Jeremiah, “You speak falsely! The Lord our God has not sent you to say, ‘Do not go to Egypt to dwell there.’ 3 But Baruch the son of Neriah has set you against us, to deliver us into the hand of the Chaldeans, that they may put us to death or carry us away captive to Babylon.”

They not only broke their vow, they did so in their self-importance, and thereby doomed the people who they were supposed to lead.

These days, our hearts are no less proud and defiant, and many have said by way of indulging themselves, “Only G-d can judge me.” And where that should frighten them, the implication is that G-d will not judge them harshly, because they don’t understand the nature of G-d. He is faithful, yes, and true, yes, but he is also just, which means that His punishments are as deserved as His blessings. His sovereignty in the final decision regarding the fate of your eternal soul will therefore not only be irrevocable, but it will be the right one.

This is why the faithless stand no chance, the unbeliever has signed his own death warrant, and the unrepentant backslider who’s renounced the atoning blood of Jesus is a son of hell.

Our own Savior tells us He does the Father’s will in such matters:

John 5:30-32 
30 I can of Myself do nothing. As I hear, I judge; and My judgment is righteous, because I do not seek My own will but the will of the Father who sent Me.

In order for the Father and Son to be of one mind and will, the Son came under obedience. Judgment is not a casual matter, but it is harsh and frightening, and the defiant will find their tongues to be silent as they tremble. The Apostle John tells us Jesus said more than once: “There will be weeping and gnashing of teeth.”

Let us be mindful that if judgement starts with the Chosen of G-d, it will likely be harsher because the Son came to them first. What chance then, for us as imperfect believers? There is no chance for the unbeliever, but they have chosen for themselves.

There’s an ad on Facebook where secularists, atheists, skeptics, and agnostics can come together; it is described as a place for ‘happy godless people’ who think they’re going to get a chance to mouth off, flip off, and mock. Here is what the disciple who Jesus loved had to say on meeting Him:

Revelation 1:17

17 And when I saw Him, I fell at His feet as dead. But He laid His right hand on me, saying to me,“Do not be afraid; I am the First and the Last.

‘…happy godless people.’

Jesus would say to us: “I tell you the truth, they have their reward.”

There are times as well when G-d assures of victory; let us not in an excess of emotion add vows to that which he told us, for He will test the truth of our words, and it may cost us dearly: (Judges 11:29-40)

Jephthah’s Vow and Victory
29 Then the Spirit of the Lord came upon Jephthah, and he passed through Gilead and Manasseh, and passed through Mizpah of Gilead; and from Mizpah of Gilead he advanced toward the people of Ammon. 30 And Jephthah made a vow to the Lord, and said, “If You will indeed deliver the people of Ammon into my hands, 31 then it will be that whatever comes out of the doors of my house to meet me, when I return in peace from the people of Ammon, shall surely be the Lord’s, and I will offer it up as a burnt offering.”
32 So Jephthah advanced toward the people of Ammon to fight against them, and the Lord delivered them into his hands. 33 And he defeated them from Aroer as far as Minnith—twenty cities—and to Abel Keramim,[a] with a very great slaughter. Thus the people of Ammon were subdued before the children of Israel.
Jephthah’s Daughter
34 When Jephthah came to his house at Mizpah, there was his daughter, coming out to meet him with timbrels and dancing; and she was his only child. Besides her he had neither son nor daughter. 35 And it came to pass, when he saw her, that he tore his clothes, and said, “Alas, my daughter! You have brought me very low! You are among those who trouble me! For I have given my word to the Lord, and I cannot go back on it.”
36 So she said to him, “My father, if you have given your word to the Lord, do to me according to what has gone out of your mouth, because the Lord has avenged you of your enemies, the people of Ammon.” 37 Then she said to her father, “Let this thing be done for me: let me alone for two months, that I may go and wander on the mountains and bewail my virginity, my friends and I.”
38 So he said, “Go.” And he sent her away for two months; and she went with her friends, and bewailed her virginity on the mountains. 39 And it was so at the end of two months that she returned to her father, and he carried out his vow with her which he had vowed. She knew no man.
And it became a custom in Israel 40 that the daughters of Israel went four days each year to lament the daughter of Jephthah the Gileadite.

Jephthah didn’t need to make the vow, as the Lord had already set things in motion for his victory by the fact that the people came to him to deliver them.

None will escape the judgement of Heaven; don’t treat it lightly.

It is perfect, final, and to be greatly feared.

Therefore I pray:

Lord, let Your Spirit ever convict me, putting a guard on my heart, and over my mouth. Let my soul be steadfast in Your presence, for you have given me the strength and wisdom to run this race, and the mercy and grace to continue fighting until my work is done.

You understand that I can’t comprehend why You love me, or why You deemed me worthy of knowing the Truth, but I am thankful that You did.  You understand my limitations, but You’ve also called me to a higher standard.

You delivered me when I made my vow, and there are days in my life I have not honored it, falling under Your righteous judgment. I vow anew, in the spirit of sorrowful repentance, to fulfill it once more, and dedicate myself to serving You in the time that remains, for You have continued to bless and sustain me.

Refresh my spirit, heal my heart, and quicken my light, that I may guide the lost to You through the work You’ve given me, that they may glorify my Father in Heaven, through faith in You.

Help me to love as You love, to see that which the Father sees in all men, and fill my hands with such seeds as You would have me plant, or give me living water to pour where You would have me water.

To the Father I would bring honor and glory, rejoicing with those whom I’ve brought to faith, that they may be delivered from justice, cut off without remedy.

I ask in faith, believing I’ve received.

May it be done to me as You have said.

Amen.