Bible Verses About Backsliding: Is departing form the simplicity of the gospel

Foolish Galatians, who has bewitched you not to obey the truth, before whose eyes Yeshua the Messiah was openly portrayed among you as crucified?

I just want to learn this from you. Did you receive the Spirit by the works of the law, or by hearing of faith?

Are you so foolish? Having begun in the Spirit, are you now completed in the flesh?