If we are convinced that (1) people are lost and (2) the gospel is the only way of salvation, then we must fervently pray for conversions. All of us have family and friends not numbered among the redeemed. We live in countries where much of the population does not know the message of the cross. And there are still large sections of the world that have not been affected by the Christian message.
A great emphasis on praying for conversions is recorded in the Bible. The Apostle Paul saw his fellow Jews as sincere and zealous for God yet ignorant of how God reconciles sinners to himself. He says, "Brothers, my heart's desire and prayer to God for the Israelites is that they may be saved." (Romans 10:1) His prayer for their conversion sprang from his desire for their salvation. He was convinced that they were lost and the gospel was their only hope of salvation.
From the day of Pentecost, the gospel was embraced by thousands of Jews. (Acts 2:41; 4:4) That growth continued as the gospel spread into the Gentile world. However, opposition from the religious authorities confronted the disciples. How they responded to such threats is most instructive: they organised a prayer meeting. "'Now, Lord, consider their threats and enable your servants to speak your word with great boldness.'… After they prayed, the place where they were meeting was shaken. And they were all filled with the Holy Spirit and spoke the word of God boldly." (Acts 4:29-31) Their personal safety was not a priority, but boldness, confidence, power to proclaim the message of Jesus and him crucified was at the top of their agenda. Paul expresses the same sentiment when he requests the Ephesian church to pray on his behalf: "Pray also for me, that whenever I open my mouth, words may be given me so that I will fearlessly make known the mystery of the gospel, for which I am an ambassador in chains. Pray that I may declare it fearlessly, as I should." (Ephesians 6:19-20)
Paul, more than anyone else, spread the gospel to parts of Asia and Europe. He requested the prayers of the believers in Thessalonica as he continued his missionary work into new territories. "Finally, brothers, pray for us that the message of the Lord may spread rapidly and be honoured, just as it was with you." (2 Thessalonians 3:1)
The Bible teaches that we must pray for conversions. There are mission fields among our families and friends and neighbours. If we follow the apostolic pattern of praying for the salvation of all people, God will hear our prayers. Our evangelistic efforts must be saturated with prayer.