The following is a post from my brother's blog and my reply which follows. I hope you all will find it interesting and helpful.
Had an interesting discussion with my old Deacon/ Sunday School leader about salvation and living the Christian life. A friend of mine mentioned doubts about salvation. I quoted some new testament scripture about believing in heart and professing with your mouth that Jesus is Lord, and you'll be saved. The question was posed in Sunday School (I wasn't there), and I guess it brought up a discussion regarding "how can belief be all that's required?", or something of the sort. The subject of the "Christian Life" came up, and I guess will be discussed further on Thursday at their Bible Study. Here's my questions-
1. Why is there a "Christian" life and a non-Christian one. Isn't there just one world that we all live in? That leads to the implication that a Christian certain duties that others don't have. This leads to my next question.
2. What duties define the Christian life? Preach the gospel? Disciple others? Go to church? Give tithes and offerings? These are all discussed in the Bible. Which leads to the third question.
3. If there is actually a separate Christian life, and if it has required duties, how much of these duties am I required to perform? If I don't do enough of them, will I not be good enough for Heaven? How much is enough? If I enjoy the duty, does that mean that it isn't a true sacrifice?
While way overly-simplified, so you see where this line of thinking/questioning takes us? In the complete opposite of Christ's teachings. If you want my opinion, I don't believe that Jesus would endorse the "Christian Life". Our culture has placed so many human-contrived ideas on what God wants of us that it has lead to a Pharacitical type list of rules and regulations that must be followed in order to be a "good Christian" (another idea that doesn't seem to line up with Christ's teachings. For instance, what's a bad Christian?)My summary- Christ walked by his disciples and said, "Follow Me." And they did. I decided to do that 23 years ago, and I believed that by following, my sins would be paid for by his death and I would be destined for Heaven. Any details that muddle this issue or cause me to doubt the truth of this are, in my humble opinion, useless and dangerous. There is life and there is death. I'll follow Christ in life, and my life will be a Christian one. Not the other way around. Trying to live a Christian life causes you to compare yourself to the "Christians" around you. Living your life while you follow Christ will, in the end, be considered a Christian life.
I think it's awesome that you are contemplating the truths that are in the Bible and what it is that God really requires of us, if anything. You are absolutely right that, once we accept Christ as our Savior, and place our faith in Him, believing that He is able to pay for our sins (which He did on Calvary) and take us to Heaven, we are saved and no amount of sin or good works will change that. I think where you may be confused is in your comments about whether or not there is a "Christian Life" we are to live, and what the consequences or rewards of that life will be.
"1. Why is there a "Christian" life and a non-Christian one. Isn't there just one world that we all live in? That leads to the implication that a Christian certain duties that others don't have. This leads to my next question."
A. I Peter 1:13-16 says:  Wherefore gird up the loins of your mind, be sober, and hope to the end for the grace that is to be brought unto you at the revelation of Jesus Christ;
 As obedient children, not fashioning yourselves according to the former lusts in your ignorance:
 But as he which hath called you is holy, so be ye holy in all manner of conversation;
 Because it is written, Be ye holy; for I am holy. Throughout the Bible there are references to living a "Holy Life". Jesus died because we fall short and he wanted to bridge that gap between us and the level of perfection God requires. We then should be grateful and not take his death for granted by continuing in the "former lusts of your ignorance". Paul said it very plainly when he said in Romans 6:1-2, " What shall we say then? Shall we continue in sin, that grace may abound?
 God forbid. How shall we, that are dead to sin, live any longer therein?" When we were living as slaves to sin, we had no hope of every having the perfection that is required to get into heaven. Now that we are saved and have Jesus' righteousness, we have His perfection. This again does not mean we should live in our old sin...Paul says "God Forbid." If we do this, we are not losing our salvation, but we are disrespecting and dishonoring Jesus.
"2. What duties define the Christian life? Preach the gospel? Disciple others? Go to church? Give tithes and offerings? These are all discussed in the Bible. Which leads to the third question."
Romans 12:1 says, " I beseech you therefore, brethren, by the mercies of God, that ye present your bodies a living sacrifice, holy, acceptable unto God, which is your reasonable service. The term "reasonable service" is referring to a "duty". Because we are no longer our own, but are bought with a price (the blood of Jesus), we no longer have a say in what we do or how we do it. I Cor 6:20 says, " For ye are bought with a price: therefore glorify God in your body, and in your spirit, which are God's. As you can see, the Bible says we belong to God. It follows then that if he asks us to honor him by performing certain duties (such as tithing, going to church, etc.) then we should do it. A Christian has essentially laid his life down as a "living sacrifice", giving it to God and relinquishing control. Fortunately, we have a God who wants a life for us that is better than we could provide for ourselves.
"3. If there is actually a separate Christian life, and if it has required duties, how much of these duties am I required to perform? If I don't do enough of them, will I not be good enough for Heaven? How much is enough? If I enjoy the duty, does that mean that it isn't a true sacrifice?"
We as Christians are required to live our lives by the example Jesus set, and the instructions God has given us in the Bible. If the Bible instructs us to do something and we truly desire to be the "living sacrifice" God has asked us to be, then we must obey. If we do not obey the Bible, WE DO NOT LOSE OUR SALVATION. This is an important point and one that is commonly misunderstood by critics of fundamental doctrine. When we are adopted into God's family and we disobey Him, we are no less a child of God than an orphan who gets adopted and disobeys his new parents. The adopted child's disobedience does not change the legal documents that were signed before a judge stating that this child is now a member of that family. While the child may be disciplined to teach him how to obey, and the child may lose out on some of the blessings and benefits that the other family members are enjoying, that child is still loved by the parents and considered their own. This holds true with our relationship to the Lord. Our level of commitment and service to Him will not determine whether or not we are going to heaven because that was settled on the cross 2,000 years ago. It will simply determine our usefulness to God here on this earth and the eternal rewards we will receive in Heaven. The only reason God doesn't immediately take us to Heaven to live with Him after we are saved is because there are still those who don't know Him here on this earth and need to hear the good news. We are here as servants of Christ.
"If you want my opinion, I don't believe that Jesus would endorse the "Christian Life"."
As a matter of fact, He did. In Matthew 5, 6, and 7 Jesus preached a rather long sermon explaining the "Christian Life" and how we are to live. He talks about issues such as lust, anger, dissention among the brethren, making frivolous vows, doing good works (verse 16), etc. Jesus is the source of the belief that we should live a Christian Life. I agree that many religious groups have added their own rules to biblical teaching, and many times this is because the principle is in the Bible (i.e. modesty) and changing times require us to adapt what the Bible says to our modern day (for instance, Jesus never said don't wear a bikini, but the Bible does define nakedness and we can ascertain from those verses that a bikini would be considered immodest).
"Trying to live a Christian life causes you to compare yourself to the "Christians" around you."
This is untrue. If you are trying to live a Christian life, then you would be living by the verse in the Bible that says, " For we dare not make ourselves of the number, or compare ourselves with some that commend themselves: but they measuring themselves by themselves, and comparing themselves among themselves, are not wise. II Cor 10:12". We are instructed to look to Jesus for our example instead of comparing ourselves to others. Paul said in Heb 12:2, " Looking unto Jesus the author and finisher of our faith; who for the joy that was set before him endured the cross, despising the shame, and is set down at the right hand of the throne of God." A person who is TRUELY living a Christian life (there are a LOT of fakers) is going to be the most humble person you've ever met because they see how much they fall short of the righteousness of Christ. Again, I'm not taking about Salvation; I'm talking about sanctification which is the process that God takes us through in our lives to help us become more Christ-like.
"Living your life while you follow Christ will, in the end, be considered a Christian life." I couldn't agree more.