But the most significant truth we are told about Lydia is that her heart was closed. In other words, it was closed to God and to Jesus Christ. It was closed very effectively to the message of salvation. Before I became a minister of the gospel I worked for a year for the National Coal Board as a wages clerk in their south-west Wales headquarters. The miners in the 20 collieries in the region were all being paid in cash in 1964, and every Thursday we would fill their wage packets from a million pounds in cash, and we would carry the metal cash-boxes for each pit into a strong room for the night before paying the miners on Fridays. The strong room had a mammoth door which two men would push closed and then turn a wheel in the middle. A fly couldn't pass that door and a burglar would find it a very considerable and lengthy challenge. That door was closed shut on Thursday nights.

That closed door is a picture of Lydia's heart, and the heart of every man and women outside of Christ, so of your heart too. The hearts of all mankind are closed to the gospel, to the preaching of the word, the beseechings and invitations of the Lord. This woman was a very capable women with considerable responsibility in the world of commerce, and I am sure she did her job with great competence and integrity, but her heart was closed. There is no mention of her husband, simply the members of her household, and she was working to support her children or her parents, and she seems to have had their trust, but her heart was closed. She was a religious person with some knowledge of the God of the Old Testament Scriptures, and one day each week was different for her, but her heart was closed. She was not simply 'dead orthodox' as the phrase puts it, but she believed in prayer and met regularly with other women and prayed. She was deeply devout, but still her heart was closed. With all her intelligence, and respectability, and business acumen, and religion, and piety her heart was closed.

There were a number of women gathered there outside the city gate by the river, and Paul spoke to every one of them with the same sincerity, yearning that every one of them should come to know his Saviour for themselves. Yet there was just one woman whose heart was opened. How solemn is this matter of the sovereignty of Christ. Many fishermen lined the shores of Galilee's lake but just two sets of brothers taken to follow Christ. You yourself once went to a meeting and there the Lord opened your heart. You thought the heart of your husband who was sitting alongside you would have been opened too but he had nothing to say of the salvation of Christ. Or you went with a gang of your friends, but afterwards they talked of football and school and music. Jehovah Jesus meant as little to them after the meeting as he had before, but you were changed. Your heart had been opened. That is how it is in this solemn and humbling experience. It is initiated by Christ. It is accomplished by the grace of Christ, and that grace works sovereignly, and selectively. That grace falls with all its particularity on favoured men and women as he determines. This is his grand prerogative, and in that honour none shall share. Please don't presume on that grace. Don't say as boys in school would say to me, "I'd like to be religious. I want to taste what the world offers first, and then when I'm older I might become religious." It is not in our power to determine the time or place. The only moment we have is now. All the years gone can never return, and all the future is unknown. We may soon be dead. Now is the time to plead with the Lord to open our heart.

What happened when the Lord opened her heart? We are told that she was able "to respond to Paul's message" (Acts 16:14). The message demanded a response. It demanded repentance for her sins. It demanded trust in the finished work of Jesus Christ. It demanded baptism and a life of discipleship, and all this was possible once the Lord had opened her heart. She heard Paul speaking and she thought, "I have never heard anyone speak like this." She thought to herself, "What an orator he is. He really believes what he says." She thought, "This is all making sense." But it was not because of Paul's eloquence or sincerity that his words were having such a transforming influence in her life. It was all due to the Lord opening her heart. I once spoke to a woman in hospital who had been involved in a minor accident outside Aberystwyth and for fear she might have had concussion they were keeping her in hospital for 24 hours. She was fed up with life, but I spoke to her about the God who is in control of all our circumstances, even the fall of the sparrow. "That God has come to this world in his Son Jesus Christ to save us," I said. She looked back bleakly to me and she said, "Words, only words." The gospel came to her, but in word only. When the gospel came to the Thessalonians it did not come in word only, but in power and with the Holy Spirit and with much assurance so that the Thessalonians received the gospel of Paul not as the word of men but as it is in truth the word of God. So it was when Lydia's heart was opened she was able to respond to Paul's message.

Douglas MacMillan and his elders were interviewing two teenage boys who had come to profess faith and were applying for church membership. "Tell us what changes have taken place in your life that would lead us to believe you have been converted," said Douglas. Their spokesman said, "Oh, it was no change in us. The change was in you, about six months ago, when your preaching got interesting." Of course it was no change in Douglas' preaching. What had happened was that the Lord had opened their hearts at that time and then the preaching seemed more relevant, and the worship more enjoyable and Sunday was no longer a boring day. So as Paul opened the Scriptures using the sword of the Spirit the same Spirit of Jesus opened Lydia's heart so that she believed what Paul said to her. She became the first convert of whom we know anything on European soil.

What an encouragement Lydia is to us all to go on praying for those whose hearts have long been closed. We sometimes have the misfortune to hear certain preachers inform us that God lacks the ability to open the heart. "God can do no more. It is all up to you," they tell proud sinners who are glad to hear that they are mightier than God, and that they can keep the Lord wringing his hands in heaven wondering whether men will condescend to accept him or not. Who would want to worship and follow such a god? If that were really the way it is then prayer itself for loved ones' salvation would be futile. Such a theology says so mournfully that God has no power to open our loved ones' hearts. Man almighty: God impotent. But that is not how it is! The Lord opened Lydia's heart and he can open the hearts of the most obdurate sinners. Pray on!

GEOFF THOMAS