This is the message you heard from the beginning: We should love one another.
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.
Do not be surprised, my brothers, if the world hates you.
We know that we have passed from death to life, because we love our brothers. Anyone who does not love remains in death.
Anyone who hates his brother is a murderer, and you know that no murderer has eternal life in him.
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.
If anyone has material possessions and sees his brother in need but has no pity on him, how can the love of God be in him?
Dear children, let us not love with words or tongue but with actions and in truth.
This then is how we know that we belong to the truth, and how we set our hearts at rest in his presence whenever our hearts condemn us. For God is greater than our hearts, and he knows everything.
Dear friends, if our hearts do not condemn us, we have confidence before God and receive from him anything we ask, because we obey his commands and do what pleases him.
And this is his command: to believe in the name of his Son, Jesus Christ, and to love one another as he commanded us.
Those who obey his commands live 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.

GNT … he who keeps His commandment dwells in Him & He in Him …

By this we know that He abides in us, by the Spirit which He gave to us’

Have you ever met that person that just oozes God’s love, the one who is always giving and helping and thinking of others first? This is evidence of the Holy Spirit working in us because the greatest Gift of the Holy Spirit is Love.