Let us love one another, for God is Love.

⁷ Dear friends, let us love one another, for love comes from God. Everyone who loves has been born of God and knows God. ⁸ Whoever does not love does not know God, because God is love. ⁹ This is how God showed his love among us: He sent his one and only Son into the world that we might live through him. ¹⁰ This is love: not that we loved God, but that he loved us and sent his Son as an atoning sacrifice for our sins. ¹¹ Dear friends, since God so loved us, we also ought to love one another. ¹² No one has ever seen God; but if we love one another, God lives in us and his love is made complete in us.
¹³ This is how we know that we live in him and he in us: He has given us of his Spirit. ¹⁴ And we have seen and testify that the Father has sent his Son to be the Savior of the world. ¹⁵ If anyone acknowledges that Jesus is the Son of God, God lives in them and they in God. ¹⁶ And so we know and rely on the love God has for us.
God is love. Whoever lives in love lives in God, and God in them. ¹⁷ This is how love is made complete among us so that we will have confidence on the day of judgment: In this world we are like Jesus. ¹⁸ There is no fear in love. But perfect love drives out fear, because fear has to do with punishment. The one who fears is not made perfect in love.
¹⁹ We love because he first loved us. ²⁰ Whoever claims to love God yet hates a brother or sister is a liar. For whoever does not love their brother and sister, whom they have seen, cannot love God, whom they have not seen. ²¹ And he has given us this command: Anyone who loves God must also love their brother and sister.
 (1 John 4:7-21 NIV)

13 If I speak in the tongues of men or of angels, but do not have love, I am only a resounding gong or a clanging cymbal. ² If I have the gift of prophecy and can fathom all mysteries and all knowledge, and if I have a faith that can move mountains, but do not have love, I am nothing. ³ If I give all I possess to the poor and give over my body to hardship that I may boast, but do not have love, I gain nothing.

⁴ Love is patient, love is kind. It does not envy, it does not boast, it is not proud. ⁵ It does not dishonor others, it is not self-seeking, it is not easily angered, it keeps no record of wrongs. ⁶ Love does not delight in evil but rejoices with the truth. ⁷ It always protects, always trusts, always hopes, always perseveres.
⁸ Love never fails. But where there are prophecies, they will cease; where there are tongues, they will be stilled; where there is knowledge, it will pass away. ⁹ For we know in part and we prophesy in part, ¹⁰ but when completeness comes, what is in part disappears. ¹¹ When I was a child, I talked like a child, I thought like a child, I reasoned like a child. When I became a man, I put the ways of childhood behind me. ¹² For now we see only a reflection as in a mirror; then we shall see face to face. Now I know in part; then I shall know fully, even as I am fully known.
¹³ And now these three remain: faith, hope and love. But the greatest of these is love. (1 Corinthians 13:1-14 NIV) 

³ We know that we have come to know him if we keep his commands. ⁴ Whoever says, “I know him,” but does not do what he commands is a liar, and the truth is not in that person. ⁵ But if anyone obeys his word, love for God is truly made complete in them. This is how we know we are in him: ⁶ Whoever claims to live in him must live as Jesus did.
⁷ Dear friends, I am not writing you a new command but an old one, which you have had since the beginning. This old command is the message you have heard. ⁸ Yet I am writing you a new command; its truth is seen in him and in you, because the darkness is passing and the true light is already shining.
⁹ Anyone who claims to be in the light but hates a brother or sister is still in the darkness. ¹⁰ Anyone who loves their brother and sister lives in the light, and there is nothing in them to make them stumble. ¹¹ But anyone who hates a brother or sister is in the darkness and walks around in the darkness. They do not know where they are going, because the darkness has blinded them.       (1 John 2:3-11 NIV)

¹⁰ This is how we know who the children of God are and who the children of the devil are: Anyone who does not do what is right is not God’s child, nor is anyone who does not love their brother and sister. ¹¹ For this is the message you heard from the beginning: We should love one another. ¹² Do not be like Cain, who belonged to the evil one and murdered his brother. And why did he murder him? Because his own actions were evil and his brother’s were righteous. ¹³ Do not be surprised, my brothers and sisters, if the world hates you. ¹⁴ We know that we have passed from death to life, because we love each other. Anyone who does not love remains in death. ¹⁵ Anyone who hates a brother or sister is a murderer, and you know that no murderer has eternal life residing in him.
¹⁶ This is how we know what love is: Jesus Christ laid down his life for us. And we ought to lay down our lives for our brothers and sisters. ¹⁷ If anyone has material possessions and sees a brother or sister in need but has no pity on them, how can the love of God be in that person? ¹⁸ Dear children, let us not love with words or speech but with actions and in truth.
¹⁹ This is how we know that we belong to the truth and how we set our hearts at rest in his presence: ²⁰ If our hearts condemn us, we know that God is greater than our hearts, and he knows everything. ²¹ Dear friends, if our hearts do not condemn us, we have confidence before God ²² and receive from him anything we ask, because we keep his commands and do what pleases him. ²³ And this is his command: to believe in the name of his Son, Jesus Christ, and to love one another as he commanded us. ²⁴ The one who keeps God’s commands lives in him, and he in them. And this is how we know that he lives in us: We know it by the Spirit he gave us.
 (1 John 3:10-24 NIV)