Why was the Savior's Atonement Necessary?

A Fallen World 
We live in a fallen world from which we will not escape unscathed by sin. Because of the Fall of Adam and Eve, the natural man of flesh will ensure that all of us make poor choices and commit sin during our mortal sojourn. The only one to ever walk this earth free of sin is Jesus Christ.

The Demands of Justice
The law of justice is an eternal law of consequences that cannot be avoided or nullified. Every action demands a reaction. Every choice we make demands a corresponding consequence. The most harmful consequence of sin is that it distances us from God. On our own, there is no way back to God until justice is satisfied with a punishment we're incapable of paying.

Distanced from God
A fullness of joy and inner peace will only be found when we are close to God. We cannot be truly happy when sin distances us from our Heavenly Father. This applies in the eternities as well. We strive to someday return to God's presence and receive all that he has in store for us, yet we cannot to so if the chasm of sin divides us from Him. The scriptures make it clear that God cannot look upon sin with the least degree of allowance and that in a sinful state we would rather hide ourselves from Him than come into his presence.

The Need for a Mediator
We all sin and fall short of qualifying to be in God's presence. We cannot bridge the gap on our own, which is why a Savior was prepared for us from before the foundation of the world. God knew we would sin and prepared a merciful way forward, a mediator to shield us from the eternal consequences of our mistakes and become our Lord. Rather than answer to the buffeting of Satan and his enslavement in sin, Jesus Christ has stepped in as our mediator, savior, and master.

The Atonement of Jesus Christ
Because justice must be paid, Jesus Christ came to earth as a sinless offering to satisfy the demands of justice for the redemption of all those who will repent and believe on His name.

THIS IS A BIG DEAL!

Without this infinite and eternal sacrifice, we would be lost forever. No event so significant ever has or ever will transpire on this planet! Every prophet since Adam prophesied of and looked forward to the coming of the Messiah. Every prophet since that time has also testified of that sacred event.

What Is Asked of Us?
The Savior simply asks that we repent and believe on Him, that we offer up a broken heart and a contrite spirit. He has already paid the price for our redemption. Now we just need to follow Him.

A Free Gift
Because Jesus broke the bands of death, we too will be resurrected. All of us. This is a free gift for everyone. I believe it's a reward for our choosing to follow Christ before this life. Nobody will be left behind in the grave - we all will have our body and spirit reunited to be brought before the bar of God.

His mercy goes one step further. For those who die before they've reached accountability or who live a lifetime without mental capacity for accountability, Christ's atoning sacrifice saves them. They never willingly transgressed the commandments and therefore need no repentance. Jesus satisfied the demands of justice for them.

It's my testimony that these things are true. I've made many mistakes and have felt the redeeming power of Jesus Christ's atonement in my own life time and time again.

(See 2 Nephi 2:5–10, 17–26; 9:5–26; Alma 34:8–16; 42:9–26.)