Actually a term which has been translated "free will" occurs in the NT, the term hekousion. κατὰ ἑκούσιον (kata heousion) has been rendered according to free will in Philemon, that Philemon should act of free will instead of necessity." The related adverb is ἑκουσίως; hekousiōs, the related adverb is in Hb 10:26.
That being said, it should also be noted that in the NT there is no specific word for "will" as a faculty of the human or of the human mind. Thelēma is a thing willed, like it is my will that you eat beans; that word does occur, but it does not mean a faculty of will.
In Philemon we read, "but without thy mind I would do nothing; that thy goodness should not be as of necessity, but of free will."
Yet we do find the Lord, at least on occasion, turning hearts.
But it is clear that the Lord wants us to act of free will in doing good. He cares that we actually love others and act out of that love. Some of us would like the Lord to take over and control our lives like the potter over the clay. We would like to experience, "I have been crucified with Christ, and it is no longer I who live, but Christ lives in me." But it goes on to say, "And the life which I live in the flesh, I live in faith."
But we ever have a necessity to trust the Lord, like Peter when he walked on the water, only to find himself soon sinking with eyes off the Lord. And there is a limit on taking over and controlling a Christian's life, else we would never sin -- but in many ways we all stumble (James). You can't even pray any prayer whatsoever now & be guaranteed you won't sin 5 minutes later!