"You were running the race so well. Who has held you back from following the truth? It certainly isn’t God, for he is the one who called you to freedom. This false teaching is like a little yeast that spreads through the whole batch of dough! I am trusting the Lord to keep you from believing false teachings..." Galatians 5:7-9 NLT italics and emphasis mine
Heinzmann in 1872 (later Fratscher in 1875) demonstrated that when a frog is placed in cold water and temperature suddenly raised, the frog would leap out but not so when temperature is raised gradually. "…when water temperature was raised at a rate of 0.002°C/s, the frog was found dead at the end of 2½ hours without having moved” (Sedgwick, William, July, 1888)
While the premise behind the experiment may not be entirely true, the truth is most of us will not respond to significant changes if imposed on us gradually. Morally and spiritually, there are things that you accept/tolerate today which you wouldn't even consider 10 years ago…beware, your environment (peers/media/exposure) are a big role in the gradual change imposition.