The Bible includes many outward actions that are symbolic of inward realities. For example, people tore their clothes to indicate distress, perhaps over some calamity or disaster, or mourning a death, or even righteous indignation over sin. Although the tearing of garments was not commanded by God, it was an outward manifestation of something that was happening on the inside.
The Lord did, however, warn His people against such a sign that was only outward. In Joel 2:13, God said, “Rend your hearts and not your garments.” They were apparently doing the outward sign apart from the inward reality. And the Lord told them to stop it.
In his New Testament letter, the Apostle James spends a great deal of time telling his readers that what is on the inside should be manifested on the outside. Over and over, James says that through our actions and our speech, there should be an outward demonstration of what God has done on the inside. The work God does in our hearts should become apparent to those with whom we interact.
The point, though, is not just to become like the Pharisees: whitewashed tombs. They looked good on the outside, but it was only the outside. Their actions and words were not a reflection of God’s work on the inside. Actually, their hearts were not truly inclined toward God at all.
God wants both. His plan is to cause us to mature in Him, both inwardly and outwardly. As we allow Him to work in our hearts, that work should become more and more evident in our lives.