Focusing on conversion is like focusing on first base in baseball. If your primary goal is getting everyone to first base, you will have quite a bottleneck there. And you can imagine, some people will get bored hanging around there and they may go back to what they were doing before. Others may become frustrated or disappointed by the plateau they've suddenly reached after such an exciting start, and perhaps give up. the And, obviously, to maintain the motif, only one person can legitimately be on a single base at a time. Therefore, the others will be targets to be tagged out. Sure, some will get the idea and run on to second base on their own. But why go through all that if you don't have to? Of course, some of this will happen regardless of our efforts (see the parable of the sower- Mt. 13). But why not do what you can to reduce the fizzle-out rate?

I am not saying to quit efforts aimed at helping people commit to follow Jesus. What I am suggesting is that we shift our focus to discipleship. This way, we are adjusting our scope to the whole process, which includes conversion. Therefore, instead of stopping at first base, we assist in taking the individual all the way through to home. If he still insists on walking away, it won't be because we are too focused on first base.

I still love what I read a number of years ago, "Jesus didn't say 'Go out and get everybody saved.' He said, 'Make disciples.'" (Mt. 18).

A side note on this verse:

"...the grammatical structure of the passage should be noted to avoid a common misunderstanding. I have heard a number of sermons on the Great Commission in which the preacher points out that the word translated as “go” is a participle and thus should be translated as “going” or “having gone”. Thus, this point of the sermon becomes: “As you are going make disciples. When you are at work, or shopping or on vacation make disciples.” Although Christians certainly ought to win people to Christ whenever the opportunity arises, the participle poreuthentes should be translated as an imperative. The Great Commission has three participles: go, baptize and teach. (Keep in mind that participles are not true verbs but are verbal adjectives.) These three participles are dependent upon the main verb “make disciples” which is an imperative or command. Therefore, the three participles (go, baptize and teach) are translated as imperatives because they receive their imperative sense from the main verb. The way to make disciples is to go, baptize and teach."

-taken from "The Great Commission" by Brian M. Schwertley

http://www.reformedonline.com/view/reformedonline/greatcomm.htm