Charles Spurgeon Commentary Hebrews 12:13-15

"and make straight paths for your feet, that that which is lame be not turned out of the way, but rather be healed. Follow after peace with all men, and the sanctification without which no man shall see the Lord: looking carefully lest [there be] any man that falleth short of the grace of God; lest any root of bitterness springing up trouble [you], and thereby the many be defiled;" — Hebrews 12:13-15 (ASV)

And make straight paths for your feet, lest that which is lame be turned out of the way; but let it rather be healed. Follow peace with all men, and holiness, without which no man shall see the Lord: looking diligently lest any man fail of the grace of God; lest any root of bitterness springing up trouble you, and thereby many be defiled;

For, alas! under the means of grace, there are many who "fail of the grace of God". They acquire something they believe is like grace, but it is not the true grace of God, and they ultimately fall from it and perish.

What we need is to have unfailing grace and the power to hold on, so that, in the end, we may inherit the crown of life. For this, however, we must look diligently.

Indeed, the best of us has good reason to suspect himself. In church fellowship, we ought to be very watchful lest the church as a whole should fail through lack of the true grace of God, and especially lest any root of bitterness springing up among us should trouble us, and thereby many be defiled.