We are to be wise in our efforts when reaching out to those who need Jesus. While I believe it is possible for anyone to be saved, there is a spectrum of people we encounter every day who's capacity to hear is unequal. One size does not fit all when talking to the unsaved.
In the American populations this is what the unsaved Spectrum looks like:
1. The Impossibles: Those who are anti the Gospel. Some are avowed proud atheists. Some have been hurt. Some are members of religions who have been taught that the Word of God is not Jesus. Your approach to them must come IF the Holy Spirit instructs you to do so. Like the Saul (Pre Paul) Jesus may appear to them in a dream or in a confrontation. When we try to reach them without this calling of the Spirit, we are not doing good evangelism. Let's figure out what God is doing and follow Him in HIS venture. Sometimes in can result in reaching these impossibles.
2. The Lost Sheep: These are those who may have been brought up in the church. May at one time gone to Sunday School. But for various reasons, sin, loss, anger, frustration, bad teaching, declining health or relationship problems no longer have anything left. Many turn to drugs, promiscuity, bad relationships, violence, crime and some even end up in prison. Some end up homeless. Some end up in poverty. While reaching them in their pain seems to be easy, if the root causes that drew them into this state is not dealt with, your evangelism to these lost ones is going to be a revolving door. It's why working with prison populations is so frustrating. The root must be dealt with FIRST. Our evangelism must begin with healing the pain.
3. The Distracted Apathetic: This group is most difficult to reach. They really don't care. They fill their lives with distractions. Music. Sports. Entertainment. They keep busy at nothing and then they die. Life is stuff and busy. They can be reached in moments of crisis, health, marriage, financial trouble. The problem in converting these is they have no idea what you are talking about. Think the jaywalkers from the Leno show. The people who are cool but profoundly ignorant. The education system and pop culture is their religion. They work but without meaning. Life is aimless. Some even do well financially, but they have no concept that or if there is an Eternal God. The one true way to reach these is find them in crisis and show them that GOD is the way out of their mess.. Unfortunately sometimes in our effort to be relevant and a friend we manage to reinforce their distractions. Our monster truck enthusiasm we feign masks our passion for Jesus which should be contagious.
4. The Lukewarm Semi-Annual Church Attender: These are sometimes Jokingly called Annual members by church leadership. You see them Christmas and New Years. They are marginally more spiritually sensitive than the distracted apathetic. They believe they are going to heaven. Have very strange theologies which include reincarnation, works salvation (I'm a good person) and thousands of new age ideas that warp their minds. Yet twice a year family kicks in. They think they need to go to church, hold a candle and get a warm feeling. These people have no hunger for God. Yet, if the spit hits the fan they will be prepared to pray. They will want some holy man or woman to come see them. They will want to come back. To minister to them and bring them into the fold will take brute truth. They are prepared to hear because deep down they have a respect without commitment. They need to be told the truth, not just about heaven and hell..but about all their family. They are willing to hear... but you will need to be insistent and clear. Lukewarmness is a disease cured only by full on apostasy or the fire of God. The middle ground is death.
5. The Seeker in Church: This is a person who is seeking after something. The Holy Spirit has called them. An empty hole is present in their life. They know it. They will float from church to church. Tune into a Christian TV or Radio program. Will buy and read a book like "Heaven is for Real". Will go to the movie. This is NOT low hanging fruit or easy. They will have a lot of questions. A manifested move of God will cause them to take notice. In truth they are still unbelievers. These are the ones who answer your altar calls. The first four categories aren't going to. The problem for evangelism is what happens after the altar call is answered. Follow up. Discipleship. Integration. Assimilation (resistance MUST become futile). Unless we help the seeker find a real relationship with Jesus and help them come to reality... The Holy Spirit has called these and we are responsible to steward them well.
Unfortunately we spend too much time on the four most difficult, arguing, debating, persuading and in the end as Paul in Athens discovered.. with little affect.
Let's do what we can with those the Spirit of God is Calling and placing in our path.. and allow him to do his work... being available to step in when crisis hits.