Spirit-filled service is a service that is conscious of human insufficiency. Notice Paul's words in2 Corinthians 10:1, " I am base among you " - or, in other words, " I don't have an impressive personality." Tradition tells us that the Apostle Paul was only 4 feet 10 inches tall. He was bald, and beset by an eye-disease. He did not have a film star-like personality. The success of his labours did not depend on any human factor, for there was nothing impressive about his appearance or his speech.
Concerning his preaching, Paul writes to the Corinthians, " I was with you in fear and much trembling " (1 Cor. 2:3). When he preached, he felt conscious of his weakness, rather than of the power of God flowing through him. This is Spirit-filled service - for, remember, that a church was established in heathen Corinth as a result of Paul's preaching.
When the Spirit of God speaks through a man, the man himself is not usually conscious of being God's mouthpiece. I'm always wary of those folk who are so sure, when they stand in the pulpit, that God is speaking through them (and who are not hesitant to say so). My experience with such people has been that God has never spoken through them at all. They've just had conceited ideas of being prophetic voices. The man through whom God speaks is usually not conscious of that fact at all. The Apostle Paul says in one of his writings, " I think I am giving you counsel from God's Spirit when I say this " (1 Cor. 7:40-LB). He was not sure whether God was speaking through him. Yet we know that it was God's Voice, for what Paul himself was unaware of it.
Spirit-filled service is one that is conscious of human insufficiency. As Paul says, " When I am weak, then I am strong " (2 Cor. 12:10). The Spirit-filled servant of God goes again and again to God,like the man in the parable, saying, " I have nothing to give others. Please give me the living bread " (Luke 11:5-8). The Lord's servant is perpetually conscious of his own insufficiency.
Let us not have any mistaken ideas of Spirit-filled service. It has no great awareness of God's power, but on the contrary of fear and uncertainty. It is only long after the labours are all over than on looking back there will be the assurance that God did indeed work through us.