What you have heard from the beginning remains in you. If it does, you also will remain in the Son and in the Father

 1 John 2:1-29

But if anybody does sin, we have an advocate with the Father—Jesus Christ, the Righteous One. He is the atoning sacrifice for our sins, and not only for ours but also for the sins of the whole world.

But if anyone obeys his word, love for God[a] is truly made complete in them. This is how we know we are in him: Whoever claims to live in him must live as Jesus did.

Anyone who loves their brother and sister[c] lives in the light, and there is nothing in them to make them stumble. But anyone who hates a brother or sister is in the darkness and walks around in the darkness. 

Reason for writing these letters:

because your sins have been forgiven on account of his name.

because you have overcome the evil one.

because you know the Father,

because you know him who is from the beginning.

because you are strong, and the word of God lives in you, and you have overcome the evil one.

Do not love the world or anything in the world. 

As for you, see that what you have heard from the beginning remains in you. If it does, you also will remain in the Son and in the Father. And this is what he promised us—eternal life.

 Why?

What Jesus has done for us, sacrifice our sins through his blood, for He loves us.

The symbol of a Christian is to love others and brothers, sisters.

How?

Be strong and trust in the Lord, and walk in the way of the Lord taught us. Looking forwrd to the way to eternal life.