How many today rest satisfied with a head religion, supposing that all is well if their creed be sound; and how many more have nothing better than a hand religion—busily engaged in what they term "Christian service." "But the Lord looketh on the heart" (1 Sam. 16:7), which includes the mind, conscience, affections and will. -AW Pink
Head Religion is a religion of knowledge. Knowing the right stuff, knowing the right things,and having the right doctrine is how you get into the Kingdom of God.
Hand Religion is a religion of good works. You get into the Kingdom by doing the right stuff, doing enough of the right stuff, being good enough, staying busy doing religious things.
Heart Religion is when it becomes part of you, part of who you are, effecting how you think, how you feel, and how you act and respond. It is not doing away with correct knowledge and understanding, and it is not doing away with good works. Rather it is a relationship with the Redeemer that changes our understanding of what is true, changes the way we think, what we think about, what we desire, what we hold as truth, and our standard of right living, resulting in a totally transformed life that brings honor and glory to God.