Nicky Gumbel suggests there are many doubts people have in this whole area of being filled with the Spirit, the principal one being: ‘If I ask will I receive?’ Jesus simply says (Matthew 7:7-8): ‘I say to you: Ask and it will be given to you.’ Jesus must have seen that they were a little sceptical because he repeats it in a different way: ‘Seek and you will find.’ And again he says a third time: ‘Knock and the door will be opened to you.’ He knows human nature and so he goes on a fourth time: ‘For everyone who asks receives.’ They are not convinced so he says a fifth time: ‘He who seeks finds.’ Again a sixth time: ‘To him who knocks, the door will be opened.’ Why does Jesus say it six times? Because He knows what we are like. We find it difficult to believe God would give us anything – let alone something as unusual and wonderful as his Holy Spirit and the gifts that come with the Spirit.
Nicky Gumbel, Alpha Questions of Life, 2007 edition, Eastbourne: Kingsway Communications, p.154.