This is part of my point. If you become a believer at age 20 you can't stipulate to what you're willing to make Jesus Lord of at age 40. All you can do is generically submit to God and begin the journey. But, a lot of the second guessing that I've seen on the matter comes from an analysis of what you aren't willing to give up at 40. It then turns into questioning whether you really, truly made the decision at age 20. That ex post facto analysis is not fair. The Lordship someone stipulates to early in life is by nature going to be incomplete and vague, so what do we make of a refusal to submit 20 years later when things get complicated?
Doug,
You wrote this further back in the thread. I had some thoughts about it at the time, but have not had time to respond to it until now.
A person is not committed to Christ because he feels that he is committed, or is submitting completely at the present moment. Whatever touches the altar is holy. When we genuinely recognize and confess Jesus as our Lord for life, we have been consecrated to a lifetime of service to Him. This is little different from the commitment we make to our wives at our weddings. When we have made such vows, our remaining married does not depend on whether we feel that we are married or not. Our marital status does not depend upon whether we are perfectly fulfilling all of our marital obligations.
If we subsequently should ever wonder whether we really made the marriage commitment, we can always check our ring finger for the proof (or even watch the videos of the ceremony!). Likewise, if someone begins to wonder whether he/she ever really made the commitment to be a disciple of Jesus, it should not be difficult to remember getting baptized (which should only have taken place after such a commitment was made).
If we marry at age 20, it doesn't matter that we are ignorant of what sacrifices and challenges may be presented to us at age 40. We have already made the unconditional commitment that, regardless what the challenges may turn out to be, we are going to stay the course and remain faithful to our vows. My wife is in good health, but we are both getting old. I married a healthy woman not knowing whether she will someday have Alzheimer's, cancer, cerebral palsy or full-body paralysis. I could not know such things, but it doesn't matter. I don't know what circumstances may change, but I am well aware of my commitment and my duty.
If such circumstantial changes would induce me to abandon my wife, then I either never made the proper marriage commitment that I said I was making at the altar, or else I have subsequently defaulted on the commitment I have made. In either case, my vows bind me, and my duty is clear. If I did not mean them at the time, I still made them and must keep them. If I am currently defaulting on them, then I must repent and return to my commitment.
Likewise, when a person is told that Jesus is the Lord, and that we must repent of our rebellion and enter into a faithful relationship with Him, our baptism is our vow, and we are under obligation to keep it, whether we later feel like doing so or not. The backslider may have never been truly surrendered, but by having previously confessed Christ and been baptized, he/she has made the lifetime commitment. Having walked away from it does not free him/her from that commitment. It only means that that person is being false to his/her vows, and must return to obedience.
This assumes, of course, that the person was originally mature enough to understand the commitment that was being made. If the gospel was preached to that person without reference to the lordship claims of Christ, then that person may never have knowingly entered into the covenant, nor agreed to its terms. In that case, the fault really falls upon the evangelist who misrepresented the gospel.
A true presentation of the biblical gospel requires that the unbeliever's conscience be confronted by the crown rights of the Messiah, and His call for repentance. The evangelist had best make sure the respondent understands what these things mean, before bringing him/her to baptism—just as the pastor will usually make sure a young couple understands the commitment that marriage involves prior to hearing their vows. That's why Jesus required people to count the cost before becoming His followers.
Counting the cost does not mean getting a full list of trials and sacrifices one will experience in their lifetime of discipleship. It means coming to Christ by a denial of oneself completely (Matt.16:24), acknowledging Him as the Lord (Rom.10:9). As in deciding to marry, nobody knows, when signing-up, what trials and self-denials may come down the pike in the lifetime that lies ahead. However, whatever the cost, none can rightfully say, "I never signed up for this!" In fact, we did sign up for "this" when we confessed Christ and made the pledge of baptism. What is called for, from the point of conversion onward, is the basic integrity of keeping one's promises.