This is John Flavel's classic work on union and fellowship with God. In a comprehensive and helpful manner Flavel helps us understand better what `keeping the heart' means. He tells us why we should take this commission seriously and speaks about there being particular times when we need to be especially wary of being distracted from our goal. He then shows how we can go on to develop a greater ability in keeping our hearts in tune with God. His advice is timeless, sensitive and profound. Flavel was an English Puritan who became a non-conformist after the `Great Ejection' of 1662. It was 10 years before he was licenced to preach again, and then only in his own home. His writings, when collected in the 19th century, filled 6 volumes. Flavel's writings are known for their practical nature. He was instrumental in promoting the `Happy Union' of Presbyterians and Congregationalists.