When someone is being encouraged to pursue the ministry, especially the pastorate, I always am the voice of caution. And I
really mean it. Here's a quote from my response of mine to another post titled
Licensure.
At least in the USA, we have had our fill of failed ministers. I consider encouraging a man towards the ministry a solemn thing indeed. As an elder in the OPC, our session would only take the full-year option for interns. Several months is not enough. At the end of the year, we discouraged several interns from pursuing the ministry. We took it all with the utmost seriousness.
I hear what you are saying here, and I myself have had to dissuade several men from pursuing full time ministry (after completing seminary). I don't have a perfect track record, however; though most of the men I discouraged are not in gospel ministry today, a couple are now profitably serving Christ's church (one after enduring a predictable train wreck early on in ministry, followed by several years out of ministry before finally returning to an effective ministry).
As for the advice to avoid the pastorate if you can do anything else (fairly common in Britain when I was growing up, especially due to Lloyd-Jones influence), again I understand the concern but find it hard to square with 1 Tim 3:1: "If anyone aspires to be an elder, he aspires to a noble task". So when young men come to me sensing a call to be a pastor, rather than discouraging them, I encourage them to view it as a call to deeper discipleship, in whatever form that may take. Just because they feel called, doesn't mean they will end up as a minister. I felt called to my homeland as a pastor, but the Lord has never opened the door for me to serve there. What he has done is open the door for other kinds of service. So too, a young man feeling called to the pastoral ministry is asking to be discipled in pursuit of the godly character of 1 Timothy 3, as well as growing in knowledge of the Scriptures, theology, church history, etc, and learning how to love people well. I would that all the young men I have ever pastored had a similar desire! Now if they don't desire to grow in Godliness, grace and a knowledge and love for people, but just aspire to the title, I can be pretty sure they aren't called (at least, not yet), but wouldn't it be a good thing for them to find that out and in the process learn more about their own hearts?
I guess what I am saying is that instead of discouraging young men who feel a sense of call, I would encourage local churches to respond by mentoring them well to explore whether the call is real. In the process, a precious opportunity for the discipleship of the young man presents itself. Even if he is not called to the pastorate, perhaps he may serve some day as a ruling elder, or simply be a godly husband and father. That time spent discerning gifting and calling will surely not be wasted.