"And this is the testimony: God has given us eternal life, and this life is in his Son. He who has the Son has life; he who does not have the Son of God does not have life." NIV translation
We have eternal life with God through His Son, Jesus Christ. If you want to overcome the world and live forever with God, it really is that simple. Although it is not popular and you may even be persecuted for saying so, there is no other way except through the Son of God.
"I write these things to you who believe in the name of the Son of God so that you may know that you have eternal life." NIV translation
God does not want us wondering whether we are saved and will spend eternity with Him. We can know for sure because of our faith in Jesus Christ whom God raised from the dead. There are many uncertain things in the world today but, by faith, we can be sure that we will live forever with God. Jesus won the victory over sin and death and we can claim that victory through Him.
"This is the confidence we have in approaching God: that if we ask anything according to his will, he hears us." NIV translation
The victory that we have is not just eternal life (even though that would be big enough) but it is also a victory for today. That same faith in God and His nature gives us confidence in talking with Him (prayer). We understand that God has the power and desire to take care of us as a good father takes care of his child. Therefore, we can ask for anything that is in His plan (will) for our lives and he listens. The hard part is in knowing what that will is but He has given us His Word and His Spirit to help us to see. Many Christians do not ask God for the things that He has planned for them and so they do not receive. This failure to ask is not because of a lack of faith in God but it is because of a lack of understanding of His will for them. There are others that ask for everything that their minds can dream up but they do not receive many of those things because God knows that they are not the best for them. Because those things are not what is best for that person, they are not a part of God's plan (will) for their lives.
"And if we know that he hears us - whatever we ask - we know that we have what we asked of him." NIV translation
If we are God's children (adopted through the blood of Jesus Christ), then we know that God listens to us. He not only listens but He also answers and we know that we have what we asked because He is able and willing to give to His children.