Jeremiah 12:14-17 is an obscure passage in the bible.
However, by inference/deduction, the bible reader can get an idea in regard to the nature of the Complex dynamic relationship between God, the Israelites (also reflective in today's world as Christians) and the Gentiles (non-Christians)
Jeremiah 12:16 New American Standard Bible 1995
(a) Then if they will really learn the ways of My people, to swear
by My name, ‘As the Lord lives,’ (b) even as they taught My people to swear by Baal, they will be built up in the midst of My people.
Jeremiah 12:16(a) is particularly interesting because it suggests the possibility of non-Christians finding salvation in God by learning the ways of Christians.
Conversely, Jeremiah 12:16(b) indicates that Christians fell into sin by learning the ways of non-Christians.
Jeremiah 12:16 reflects a "pendulum"-like nature of the dynamic relationship between Christians & non-Christians—it could go either way.
From my perspective, as I read the aforementioned bible passage, Jeremiah 12:16-17 verses bring to my mind a metaphorical pendulum regarding the relationship between
- Israelites (reflective of today's world as Christians)
- Gentiles (non-Christians)
The reason why I think the relationship is like a pendulum is that it can swing either way.
In other words, either the desirable outcome prevails, which involves Christians bringing the good news of Jesus Christ to the non-Christians so that they can sincerely accept Jesus Christ.
Or
The pernicious outcome prevails, which is that Christians stray away from the True Lord by following the ways of non-Christians.

Incidentally, one should mention that Jeremiah 12:16 evokes the following verses of warning:
1 Peter 2:12 New American Standard Bible 1995
Keep your behavior excellent among the Gentiles, so that in the thing in which they slander you as evildoers, they may because of your good deeds, as they observe them, glorify God in the day of visitation.
2 Corinthians 6:14 New American Standard Bible 1995
Do not be bound together with unbelievers; for what partnership have righteousness and lawlessness, or what fellowship has light with darkness?
Deuteronomy 7:3 New American Standard Bible 1995
Furthermore, you shall not intermarry with them; you shall not give your daughters to their sons, nor shall you take their daughters for your sons.
Joshua 23:12-13 New American Standard Bible 1995
12 For if you ever go back and cling to the rest of these nations, these which remain among you, and intermarry with them, so that you associate with them and they with you, 13 know with certainty that the Lord your God will not continue to drive these nations out from before you; but they will be a snare and a trap to you, and a whip on your sides and thorns in your eyes, until you perish from off this good land which the Lord your God has given you.
Nehemiah 13:25 New American Standard Bible 1995
So I contended with them and cursed them and struck some of them and pulled out their hair, and made them swear by God, “You shall not give your daughters to their sons, nor take of their daughters for your sons or for yourselves.
Furthermore, Jeremiah 12:14-17 also evokes & gives credibility to the bible verses, John 17:11 & John 17:14-16. The reason is that God views understandably as a premise that Christians will be "in the world" with non-Christians, but are warned to be "not of the world"
John 17:11 New American Standard Bible 1995
I am no longer in the world; and yet they themselves are in the world, and I come to You. Holy Father, keep them in Your name, the name which You have given Me, that they may be one even as We are.
John 17:14-16 New American Standard Bible 1995
14 I have given them Your word; and the world has hated them, because they are not of the world, even as I am not of the world. 15 I do not ask You to take them out of the world, but to keep them from the evil one. 16 They are not of the world, even as I am not of the world.