Jesus’ Eternal Command: Love
God's Singular Command Leads to Eternal Life
Starting in Passover Jesus tells us that everything he says is Commanded by God. And, that the command *(singular) he gives will lead to eternal life.
John 12:48-50 CSB
The one who rejects me and doesn’t receive my sayings has this as his judge: The word I have spoken will judge him on the last day.  For I have not spoken on my own, but the Father himself who sent me has given me a command to say everything I have said.  I know that his command is eternal life. So the things that I speak, I speak just as the Father has told me.
Still in Passover Jesus tells us EXACTLY what the command that leads to eternal life is and how we identify each other.
John 13:34-35 CSB
“I give you a new command: Love one another. Just as I have loved you, you are also to love one another.  By this everyone will know that you are my disciples, if you love one another.”
John 15:12-14,17 CSB
“This is my command: Love one another as I have loved you.  No one has greater love than this: to lay down his life for his friends.  You are my friends if you do what I command you.  “This is what I command you: Love one another.”
1 John 4:7-21 CSB
Dear friends, let us love one another, because love is from God, and everyone who loves has been born of God and knows God.  The one who does not love does not know God, because God is love.  God’s love was revealed among us in this way: God sent his one and only Son into the world so that we might live through him.  Love consists in this: not that we loved God, but that he loved us and sent his Son to be the atoning sacrifice for our sins.  Dear friends, if God loved us in this way, we also must love one another.  No one has ever seen God. If we love one another, God remains in us and his love is made complete in us.  This is how we know that we remain in him and he in us: He has given us of his Spirit.  And we have seen and we testify that the Father has sent his Son as the world’s Savior.  Whoever confesses that Jesus is the Son of God—God remains in him and he in God.  And we have come to know and to believe the love that God has for us. God is love, and the one who remains in love remains in God, and God remains in him.  In this, love is made complete with us so that we may have confidence in the day of judgment, because as he is, so also are we in this world.  There is no fear in love; instead, perfect love drives out fear, because fear involves punishment. So the one who fears is not complete in love.  We love because he first loved us.  If anyone says, “I love God,” and yet hates his brother or sister, he is a liar. For the person who does not love his brother or sister whom he has seen cannot love God whom he has not seen.  And we have this command from him: The one who loves God must also love his brother and sister.
Matthew 5:43-48 CSB
“You have heard that it was said, Love your neighbor and hate your enemy.  But I tell you, love your enemies and pray for those who persecute you,  so that you may be children of your Father in heaven. For he causes his sun to rise on the evil and the good, and sends rain on the righteous and the unrighteous.  For if you love those who love you, what reward will you have? Don’t even the tax collectors do the same?  And if you greet only your brothers and sisters, what are you doing out of the ordinary? Don’t even the Gentiles do the same?  Be perfect, therefore, as your heavenly Father is perfect.”
2 Peter 1:5-11 CSB
For this very reason, make every effort to supplement your faith with goodness, goodness with knowledge,  knowledge with self-control, self-control with endurance, endurance with godliness,  godliness with brotherly affection, and brotherly affection with love.  For if you possess these qualities in increasing measure, they will keep you from being useless or unfruitful in the knowledge of our Lord Jesus Christ.  The person who lacks these things is blind and shortsighted and has forgotten the cleansing from his past sins.  Therefore, brothers and sisters, make every effort to confirm your calling and election, because if you do these things you will never stumble.  For in this way, entry into the eternal kingdom of our Lord and Savior Jesus Christ will be richly provided for you.
1 Peter 1:22 CSB
Since you have purified yourselves by your obedience to the truth, so that you show sincere brotherly love for each other, from a pure heart love one another constantly,
The Commandment: Eternal Since the Beginning
Here is the Commandment that has always existed since the very Beginning.
1 John 2:7-10 CSB
Dear friends, I am not writing you a new command but an old command that you have had from the beginning. The old command is the word you have heard.  Yet I am writing you a new command, which is true in him and in you, because the darkness is passing away and the true light is already shining.  The one who says he is in the light but hates his brother or sister is in the darkness until now.  The one who loves his brother or sister remains in the light, and there is no cause for stumbling in him.
1 John 3:11-15,18-19,23-24 CSB
For this is the message you have heard from the beginning: We should love one another,  unlike Cain, who was of the evil one and murdered his brother. And why did he murder him? Because his deeds were evil, and his brother’s were righteous.  Do not be surprised, brothers and sisters, if the world hates you.  We know that we have passed from death to life because we love our brothers and sisters. The one who does not love remains in death.  Everyone who hates his brother or sister is a murderer, and you know that no murderer has eternal life residing in him.  Little children, let us not love in word or speech, but in action and in truth.  This is how we will know that we belong to the truth and will reassure our hearts before him  Now this is his command: that we believe in the name of his Son, Jesus Christ, and love one another as he commanded us.  The one who keeps his commands remains in him, and he in him. And the way we know that he remains in us is from the Spirit he has given us.
2 John 1:1-6,9-11 CSB
The elder: To the elect lady and her children, whom I love in the truth—and not only I, but also all who know the truth—  because of the truth that remains in us and will be with us forever.  Grace, mercy, and peace will be with us from God the Father and from Jesus Christ, the Son of the Father, in truth and love.  I was very glad to find some of your children walking in truth, in keeping with a command we have received from the Father.  So now I ask you, dear lady—not as if I were writing you a new command, but one we have had from the beginning—that we love one another.  This is love: that we walk according to his commands. This is the command as you have heard it from the beginning: that you walk in love.  Anyone who does not remain in Christ’s teaching but goes beyond it does not have God. The one who remains in that teaching, this one has both the Father and the Son.  If anyone comes to you and does not bring this teaching, do not receive him into your home, and do not greet him;  for the one who greets him shares in his evil works.
Trusting in God's Definition of Love
Let’s examine the biblical definition of love, which is a reflection of God’s character. It’s important to remember that we are placing our trust in these qualities of God’s character for our eternal salvation.
1 Corinthians 13:4-8 CSB
Love is patient, love is kind. Love does not envy, is not boastful, is not arrogant,  is not rude, is not self-seeking, is not irritable, and does not keep a record of wrongs.  Love finds no joy in unrighteousness but rejoices in the truth.  It bears all things, believes all things, hopes all things, endures all things.  Love never ends.
1 Peter 4:8 CSB
Above all, maintain constant love for one another, since love covers a multitude of sins.