I was once experienced the provision of God, in fact I have experienced much of His grace...
And those experiences made me realized that, in fact God just looks at our 'availability' not much about our 'ability' and it is a true sayings.
In the Bible, we won't find any great men that really or truly possess what we called today as 'Diploma, PHD, Master Degrees, etc.' Back in those days, i can hardly imagine what they called those qualifications. The great men in the Bible, those are the ones that God chose according to God's own will and His own preference, it's up to God for whom He chose to do the kingdom work.
It's up to God, not qualifications, not men.
It is not based on what one possesses, but according to God's plan and I believe God looks into our hearts and He knows whose hearts are right with Him, not that qualifications can judge or decide.
'Availability' - one who will make the time for doing God's work, one who is willing to take on God's call to do what pleases God. One that will make himself/herself available whenever God calls him/her, one who is spirit-led, that he/she would follow the promptings in his/her heart.
'Ability' - in truth, it is all God-given. For some they might still give credit to themselves and think they have earned it. I am not talking about non-believers but also believers. 'Ability' is God-given, it's built in before we were ever been born. Therefore, no men can actually boast before God.
In fact, either you make yourself available for God's use or you have great abilities to do great things for God, no men can indeed boast about it, either availability or ability.
The sufficiency of God back us up....He gives us the talents we need to accomplish His task, He gives us a 'willing' heart to serve Him willingly and a 'willing' heart to make time for our God.