The religious Jews of Jesus' day had more than just the Law of Moses to keep; they also had centuries of customs, traditions, and rabbinical commandments to observe (Mark 7:3-4). The only religion they knew was one of works, and consequently they wondered what new works might be required by the teachings of Jesus. Imagine, then, their surprise at the Lord's wonderfully simple reply: "This is the work of God, that ye believe on him whom he hath sent."
Jesus Christ is the same yesterday, today, and forever (Heb. 13:8). In this modern age of non-stop activity, mission trips, conferences, and programs, believing on Him is still the only work we are required to do. Believing on Jesus is different from believing in Jesus (Jas. 2:19-20). Much more than mental assent to the truth of the Gospel, it is a relationship of complete yieldedness and trust that we live out every day. As we do so, the Holy Spirit will guide us into the foreordained paths of God's will so that He can do His works through us (Eph 2:10). Since these works are His and not ours, we have nothing to trust in for our righteousness - nothing except the finished work of the Son of God, both now and for eternity (Gal 2:20).
All Scripture references from KJV. Commentary ©2012 Hitchcock Family Ministry. Unaltered text may be reproduced freely without financial gain. Original commentary and Scripture song available at http://www.freescripturesongs.org/this-is-the-work-of-God.