I John 5:11-12 All who believe in the Son of God know that this is true. Those who don't believe this are actually calling God a liar because they don't believe what God has testified about his Son. And this is what God has testified: He has given us eternal life, and this life is in his Son. So whoever has God's Son has life, whoever does not have his Son does not have life.
John is talking about the evidence that determines whether or not we are truly God's children, our love for God and people. God is love and His children are lovers. It can be no other way. Christians are distinctly different than non-Christians in this. Non-Christians are first and foremost lovers of themselves. Christians are first and foremost lovers of God and then others. As believers we must love ourselves, but it doesn't stop there.
It is a very serious thing to call God a liar, but when we live like we are nothing more than lovers of self, aren't we in essence doing just that? God says that His children love beyond themselves and when we act differently, we are by practice saying that what God says is not true. We cannot indeed by His children if we can't or won't love those for whom Christ died.
Jesus is the greatest testimony of what God's love is like. He was sent by God to die for our sins, and that is exactly what He did. In Christ we have eternal life because He broke the back of the law's condemnation on sin. He did what no one else could do; He satisfied the just wrath of God against sin. He who knew no sin became our sin sacrifice.
Whoever lives in Christ has eternal life with God, and whoever does not live in Christ does not have life and is doomed to an eternity in hell. There is no wiggle room in this.
Is Jesus your Savior today? Are you loving others even as you are loved by Him?