Those whom God sets free are “free indeed”. But being “free indeed” includes being free to return to bondage if you prefer that to the liberty you are given in Christ. Paul pleaded with the Galatians to “stand fast in the liberty wherewith Christ has made you free and do not be entangled again with the yoke of bondage” (5:1).
If you are not free to return to sin, you are not really free at all. When you are freed by the blood of Christ from sin, you are free to return to it, and sadly, many have made that choice (2Pet. 2:22). When you are healed by the love of God of a broken heart, you are free to return to the pain. When you are healed by the power of God of a disease, you are free to be sick again if you choose to live the kind of life that takes you there. Jesus warned people of this (Jn. 5:14). When you are delivered by the wisdom of God from debt, you are free to fall back into it. The freedoms that Christ gives are perfect freedoms, and that means you are free not to have them if you prefer your former condition.
Many reasons are offered by those who choose not to remain free. But the truth always is that they do not love the “liberty of the sons of God” and they refuse to bear the responsibilities toward others that come with that liberty.
The freedom of Christ is the freedom to be like Christ. And that means the freedom to love people the way Jesus loves people. That is what those who return to darkness prefer not to do.