Heart-felt prayer is more important than most of us realise.  It comes from a deep desire and hunger that God will act in Sovereign power.  Most of the Apostles' prayers in the Bible asked God to bring strength, wisdom and spiritual insight to believers - to whole churches, leaders or individuals.  But here, Paul expressed His deep inner passion that the Jews might be saved through receiving and believing the gospel of Christ.  It follows on from His willingness to be condemned for ever, if only the Jews could be saved (Romans 9:1-5).

Although Paul was glad that they were seeking God, he was overwhelmingly sad that they were not finding Him because they did not go through Jesus.  Although all of the Old Testament pointed forward to Jesus Christ as the One who would fully satisfy God's law, most of the Jews could not see it - any more than Paul could before Jesus faced him on the road to Damascus (Acts 22:3-13).  

The Apostle knew that only Jesus could open spiritually blind eyes, as his had been.  He knew his responsibility: to preach about the crucified Saviour, and teach believers how to live as children of God (Acts 26:15-18).  But Paul also knew that only the Lord could enable them to believe and obey what they heard.  That is why he prayed so fervently.

Believers who love their unsaved friends and family (even a tribe or nation), and love their Saviour, will open their hearts to God in prayer.  Like Paul, their prayer will not just be for their problems to be resolved, but that they might hear the gospel, believe in Jesus, receive the Holy Spirit and learn to live as children of God.  Such prayer may go on for many months or years, but the Lord knows the right time to act.  Our tasks are to share the truth about Jesus and to pray that He will save them: and of those activities the work of prayer can be the most demanding, but essential.  Do not just hide sadness in your heart, but pray for those who need the Lord, and speak the truth until God gives His answer.