Hebrews 10:26 (KJV)

And having an high priest over the house of God;

Let us draw near with a true heart in full assurance of faith, having our hearts sprinkled from an evil conscience, and our bodies washed with pure water.

Let us hold fast the profession of our faith without wavering; (for he is faithful that promised;)

And let us consider one another to provoke unto love and to good works:

Not forsaking the assembling of ourselves together, as the manner of some is; but exhorting one another: and so much the more, as ye see the day approaching.

But a certain fearful looking for of judgment and fiery indignation, which shall devour the adversaries.

He that despised Moses' law died without mercy under two or three witnesses:

Of how much sorer punishment, suppose ye, shall he be thought worthy, who hath trodden under foot the Son of God, and hath counted the blood of the covenant, wherewith he was sanctified, an unholy thing, and hath done despite unto the Spirit of grace?

For we know him that hath said, Vengeance belongeth unto me, I will recompense, saith the Lord. And again, The Lord shall judge his people.

It is a fearful thing to fall into the hands of the living God.