"You, dear children, are from God and have overcome them, because the one who is in you is greater than the one who is in the world." NIV translation
We, as Christians, have overcome the evil spirits through God living in us. The one who is in us (Holy Spirit) is greater than Satan and gives us the power to see and understand the things of God.
"They are from the world and therefore speak from the viewpoint of the world, and the world listens to them." NIV translation
In the world today, we are taught that everyone's opinion is equal and should be valued. Here, we see that even those that reject God are free to speak but we are told to not listen to what they have to say because it comes from the spirit of antichrist and is of the world. We are in this world but it is not our home and we are not of this world.
"We are from God, and whoever knows God listens to us; but whoever is not from God does not listen to us. This is how we recognize the Spirit of truth and the spirit of falsehood." NIV translation
We proclaim the very Word of God and those that He has called listen and understand through the power of the Holy Spirit. Those that do not listen are not called by God and follow a spirit of falsehood. We know that all lies (falsehood) come from Satan who is the father of lies.
"Dear friends, let us love one another, for love comes from God. Everyone who loves has been born of God and knows God. Whoever does not love does not know God, because God is love." NIV translation
John gives us a second test so that we can tell whether a person is a Christian or not (who their daddy is). This test is to see if they love. He explains to us that God is love and so, if you are His child, you will love people. This is talking about a sacrificial love as we saw in chapter three. This love is putting the wants and needs of others ahead of our own and we are told that, if we do not have this love, we do not know God.