Nathanael was a skeptical guy. He seemed to be a no nonsense sort of person who was not given to just accepting out of hand what other people told him. There is nothing wrong with being a bit skeptical, but it does become a problem when skepticism becomes a point of pride or honor. God will not reach those who "think more highly of themselves than they ought to."
God desires that "none should be lost." He was calling Nathanael. In His ongoing mission to bring us all to faith in the atonement that has been made for all people in the person of His Son, Jesus Christ, He uses ordinary people like you and me to witness to our acquaintances however we might know them (I am assuming you to be a Christian). He only has two requirements of us and those are that that we come to know and apprehend Him through His Word, and that through this understanding we are willing to submit to Him and be led by His Spirit. It is important that we meet these criteria because believe it or not the world that we are appealing to are only interested in the real deal. They can make out phonies. They are not interested in our attempt at times to make either heaven or (more relevantly at this point in time) this earthly life into the fantasies that we want them to be. People would much rather just have the facts. God Himself through His Spirit is the only One able to convince them. He will save them from their sin.
Fortunately Nathanael knew somebody who took seriously this duty and vocation as a friend. Philip was willing to share with his friend what he had come to see: That Jesus was "the One whomMoses in the law, and the prophets, did write..." (Joh 1:45). Funny how he was willing to share with his unbelieving friend at that point in time what most Christians today are barely aware of, i.e. the law. This was as clear of a testimony as could be given at that point in time. In contrast to today when we try and make Jesus more palatable to those whom we are given to witness to, Philip went right to the heart of the situation with his friend. Paraphrasing: "This is the One whom God has sent to deal with our struggle against sin." Because of his friend's directness, Nathanael was willing to hear more, even go and see this Jesus for himself. Once he got there, Jesus knew exactly what needed to be said and done.
Be willing to be like Philip. Tell your friends about Jesus. Speak to them realistically when the opportunity presents itself (it will) about the freedom from sin that God has made available to them in Christ. Don't sugar-coat it for them. The time is short. "Today is the day of Salvation." Remember that Jesus your King has rescued you from the skepticism of this world. He wants to preach through you that Jesus has been raised from the dead and they are no longer in bondage to their sin. Tell all your friends and family, co-workers and other acquaintances that you want to take them to meet Jesus. My prayer for you is that you belong to a church that does not try to prevent Jesus from being seen. My advice to you at that point in time would be to join us Lutherans. Kyrie eleison