All believers need more encouragement than most people think, as they seek to follow Jesus. They look to pastors and teachers in the same way that the early Christians looked to Paul and his apostolic team.  There is often a presumption that because God's servants keep on giving sacrificially to their flock, they do not need any encouragement themselves.  That is far from true (Romans 15:30).  And if their ministry is supported by your gifts, you have not paid them to be your servants, but to be released to be ministers of the gospel of Christ.
 
Paul was greatly heartened by Timothy's report when he returned from Thessalonica, dispelling thoughts that the church had been crushed by persecution or had turned against him.  Hostility and opposition to the gospel had become routine for the apostle, and he had prayed most earnestly that the church in Thessalonica would be spared the worst of what he had experienced (2 Corinthians 11:23-28).  Most of all, he was overjoyed to learn that their faith in the Lord Jesus Christ was strong and growing.
 
Like concerned parents who are relieved to know that their offspring are safe, Timothy's positive news enabled the apostolic team to be reassured and continue in ministry with great joy.  The Lord had answered their prayers; their gospel work had not been in vain (2 Corinthians 6:1).  Their intercessions for the welfare of the church turned to praise and a renewed longing to invest more teaching in Thessalonica in the future.  God had taken their ministry and used it to build a church of people who were glad to follow Jesus, despite opposition (1 Thessalonians 1:2-10).
 
Do not assume that the Bible teaching and pastoral ministry you receive is your right to be demanded: it is a privilege, a gracious gift of God which demands a response of obedience and praise.  Of the ten lepers who Jesus healed, only one came back to give praise to God (Luke 17:15-19).  Perhaps Jesus was teaching the disciples not to rely on positive feedback from everybody, but it was certainly right that one did return to thank the Lord for the ministry he had received.  God is building you into His church to worship and serve Him, but it usually comes at considerable personal cost to those who have been gifted as teachers and pastors.  Do you thank God for them, letting them know how you are growing in your faith?  They need a little encouragement too as they pray for you and watch over your spiritual welfare (Hebrews 13:17).  It will spur them on to joyfully minister more to you and to others, strengthened by the knowledge that the Lord has used them to help you.