Aubrey Malphurs helpfully advises church planters not to ‘overemphasize or denigrate numerical growth’.
I suspect it’s the denigrating numerical growth that English-born ‘conservative’ evangelicals like me find all too easy. Hence our instant suspicion of anything big and visionary that talks in 'success' language (i.e. anything American).
But here’s the fact of the matter: numerical growth matters.
Perhaps you’ve heard it said ‘it’s not numerical growth that counts but spiritual growth’. Of course, the reality is that both spiritual growth and numerical growth matter, and the two shouldn't be divorced.
God wants to save large numbers of people.
We could go to many bible texts to show this, from the uncountable multitude in Revelation 7 to the dramatic harvest in the parable of the sower (Mark 4). We should pray, plan, and work for numerical growth.
Of course this should be qualified by a thousand qualifications about how dangerous it can be to focus on numbers. The trouble is that sometimes the importance of numerical growth is suffocated under a pile of qualifications and we sit on our conservative bottoms not going for numerical growth all the while patting ourselves on the back for not being like 'other men' (usually Hybels and Warren). So I’m not going to mention the warnings and dangers of going for numerical growth because if you’re
a. English or
b. Conservative evangelical
you’ve already thought of them all!
Since every extra number represents a person in the new earth instead of hell, how can numbers not matter? Since part of the God-honouring wonder of the eschatological Church is its sheer size, how can numbers not matter?
God wants his saved people to become like Christ.
Actually, this is an important part of the nature of the salvation of God – that his people are transformed into true human beings in the likeness (and for the everlasting glory) of his Son, Jesus Christ the second Adam, the true Israel, the Author and Finisher of our faith. So of course we must invest our time in growing in maturity in Him. And since God’s people must persevere and grow if they are to make their calling and election sure, true numerical growth that counts into eternity cannot be divorced from growth in maturity.
The answer is not either or, but how to make sure we integrate the two, as a growing church must aim for maturity or else its growth will amount to nothing, and as a maturing church that wants to continue maturing must aim to keep growing.
 Aubrey Malphurs, Planting Growing Churches for the 21st Century (Grand Rapids, Michigan: Baker Book House, 1992) p.63