1. We are all sinners.
As it is written, There is none righteous, no, not one:
ROMANS 3:10
For all have sinned, and come short of the glory of God;
ROMANS 3:23

2. God sets a death penalty for sin.
For the wages of sin [is] death;....
ROMANS 6:23
And whosoever was not found written in the book of life was cast into the lake of fire.
REVELATION 20:15
But the fearful, and unbelieving, and the abominable, and murderers, and whoremongers, and sorcerers, and idolaters, and all liars, shall have their part in the lake which burneth with fire and brimstone: which is the second death.
REVELATION 21:8

3. But why should we be accountable to God?
In the beginning God created the heaven and the earth.
GENESIS 1:1
And God said, Let Us make man in Our image, after Our likeness: and let them have dominion over the fish of the sea, and over the fowl of the air, and over the cattle, and over all the earth, and over every creeping thing that creepeth upon the earth.
So God created man in His [own] image, in the image of God created he him; male and female created he them.
GENESIS 1:26-27

For by Him [Jesus Christ] were all things created, that are in heaven, and that are in earth, visible and invisible, whether [they be] thrones, or dominions, or principalities, or powers: all things were created by him, and for him: And He is before all things, and by Him all things consist.
COLOSSIANS 1:16-17