Prayer imparts wisdom and strength to us, as we pray, and to those whom we pray for. We have been admonished to pray for others because it can help them do their work better because God will be with them. Even the great apostle Paul asked the church members to pray for him so that he could do his job better to further God’s work:

And pray in the Spirit on all occasions with all kinds of prayers and requests. With this in mind, be alert and always keep on praying for all the saints. 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.
Ephesians 6:18-19 (NIV)

It is therefore good to pray for others as they serve the Lord in their lives and their work.