The two scariest things I can imagine about Judgment Day:

1. Judgment will cover EVERYthing.

Every secret action –

God will bring every work into judgment, Including every secret thing, Whether good or evil.
(Ecclesiastes 12:14)

We must all appear before the judgment seat of Christ, that each one may receive the things done in the body, according to what he has done, whether good or bad.
(2 Corinthians 5:10)

Every idle word –

For every idle word men may speak, they will give account of it in the day of judgment.
(Matthew 12:34, 36)

Every idle thought –

[Jesus says in that context that] Out of the abundance of the heart the mouth speaks. … [So when He adds,] By your words you will be justified, and by your words you will be condemned. (Matthew 12:34, 37) [we could substitute, “by your HEART you will be justified, and by your HEART you will be condemned…”]

[And in the passage that warns us,] Do not harden your hearts. … [we learn WHY:] For the word of God is living and powerful, and sharper than any two-edged sword, piercing even to the division of soul and spirit, and of joints and marrow, and is a discerner of the thoughts and intents of the heart. 13 And there is no creature hidden from His sight, but all things are naked and open to the eyes of Him to whom we must give account. (Hebrews 4:7, 12-13)

2. Judgment begins at the house of God.

(As in the days of Peter,) The time has come for judgment to begin at the house of God; and if it begins with us first, what will be the end of those who do not obey the gospel of God? 18 Now “If the righteous one is scarcely saved, Where will the ungodly and the sinner appear?” (1 Peter 4:17-18)

It's no benefit to be closer to God than the people around you. We have to be ONE with God, who is pure and holy, and we have fallen short. (Romans 3:23)

The two most comforting things I can imagine about Judgment Day:

1. Jesus offers glory to those who follow Him.

Rejoice to the extent that you partake of Christ's sufferings, that when His glory is revealed, you may also be glad with exceeding joy. 14 If you are reproached for the name of Christ, blessed are you, for the Spirit of glory and of God rests upon you. On their part He is blasphemed, but on your part He is glorified. 15 But let none of you suffer as a murderer, a thief, an evildoer, or as a busybody in other people's matters. 16 Yet if anyone suffers as a Christian, let him not be ashamed, but let him glorify God in this matter. ... Therefore let those who suffer according to the will of God commit their souls to Him in doing good, as to a faithful Creator. (1 Peter 4:13-16, 19)

Even the terrifying passage about “flaming fire” and “taking vengeance on those who do not know God and who do not obey the gospel” and “punishment with everlasting destruction from the presence of the Lord” speaks of believers being “glorified” in Christ. (2 Thessalonians 1:10-12)

2. Jesus' blood can wash away EVERY sin. (I.e., His sacrifice can cover EVERYthing.)

Now, once at the end of the ages, He has appeared to put away sin by the sacrifice of Himself. 27 And as it is appointed for men to die once, but after this the judgment, 28 so Christ was offered once to bear the sins of many. To those who eagerly wait for Him He will appear a second time, apart from sin, for salvation. (Hebrews 9:26b – 28)

Two “burning” questions:

When we speak of the blood of Christ washing away sins, we mean that His death can pay the penalty for our sins (because He had none of His own). This is a most gracious and merciful offer by God, but does not happen automatically. God offers to extend us His grace if we meet His terms. Without going into great detail here, let's assume that it's common Bible knowledge that people must believe in Jesus and confess their faith, then turn from their sins. Is that sufficient for the blood of Jesus to be applied to our souls?

There are two important passages that tie together the concept of Jesus' blood and our forgiveness, and both have to do with another requirement for us in order to accept God's grace on His terms. Here are the two passages, offered as an answer to two burning questions:

1. We know the blood of Jesus “cleanses the conscience.” (Hebrews 9:14)

What ELSE is said to cleanse the conscience?

Answer: Baptism. 1 Peter 3:21 – There is also an antitype which now saves us—baptism (not the removal of the filth of the flesh, but the answer of a good conscience toward God), through the resurrection of Jesus Christ…

2. We know the blood of Jesus was “shed… for the forgiveness of sins.” (Matthew 26:28)

What ELSE is “for the forgiveness of sins”?

Answer: Baptism. Acts 2:38 – “Repent, and let every one of you be baptized in the name of Jesus Christ for the remission of sins.”

Are you eager for His return?
Have you accepted God's terms for forgiveness?
Have you been baptized “into His death” (Romans 6:3-4) and made contact with His blood?
Has your conscience been cleansed by the blood of Jesus? (1 Peter 3:21)
Have you been baptized in the name of Jesus for the forgiveness of sins? (Acts 2:38)

If you can answer ‘yes' to all these, you can have comfort, and no fear, in the Judgment Day.