Take a look at 2nd Cortinthians 5:17. This verse says "Therefore, if anyone is in Christ, he is a new creation; the old has gone, and the new has come!"

Did you feel differently right after you became a believer? How about a week after? How about a year after? There's no arguement here. When we are first saved by God's grace, we have this fiery zeal for him no matter what age you are. You think "Wow! My life has really changed!". But for some people, that zeal doesn't last long. The thought of being saved gets pushed back in our minds... almost like we take it for granted because we're "safe" and going to heaven. But, that's not the kind of relationship Jesus wants with us. "Religion" isn't with whom we need the relationship.

The term "born again" isn't in this verse, but it's implied. "... if anyone is in Christ, he is a new creation...". "New creation" means that we have to let go of our wordly behaviors in which we were born into sin, and start behaving like Christ. If we don't, we're using the bible in the same way we would be using a map of Indiana to get California or New York. We would get the general direction of which way to go, but in the big picture it wouldn't do much for us.

In 1st Corinthians 2:14, the bible says "The man without the Spirit does not accept things that come from the Spirit of God, for they are foolishness to him, and he cannot understand them, because they are spriritually discerned."

Again, wordly believers seem to back off from things that seem radical to them about God. These are the believers that have accepted Christ, yet continue to live in the world and not of God. A true, spiritual believer with a good relationship with Jesus would give God the praise for an answered prayer. A wordly believer would think that the good came from the work of man. A wordly believer stands and says "I'm a Christian, and proud of it". A spiritual believer acts like he's a Christian, and is proud of it.

Many times, even spiritual believers act like wordly believers. Living in the world, it's hard to stay out of it and the sinful things that come with it. The best way to stay a spiritual believer is to constantly pray, without ceasing, and surround yourself with others who are striving for that perfect relationship with Jesus, for you are in this world, but you are not of it.