What does the Bible say about safeguarding God's gospel?

In Galatians 2, Paul stresses the necessity of safeguarding the gospel against infiltrators who seek to undermine the liberty we have in Christ. He describes false brethren who have secretly come in to spy on the freedom believers enjoy, with the aim of bringing them back into spiritual bondage. This highlights the importance of being vigilant in upholding the truth of the gospel, recognizing that even a little leaven can corrupt the whole lump (Galatians 5:9). The gospel must be protected and defended vigorously to ensure that the message of grace remains pure and untainted by human error or legalism.