The heart of a wise man is in his right side; and the heart of a fool is in his left side.Ecclesiastes 10:2 (Wycliffe)
We naturally possess certain character traits. Some are positive. Others are not. God wants us to change our negative character traits. Ecclesiastes 10 characterizes the result as a shift of our heart.
We are born with our heart on the left side of our chest. But God does not want us to remain who we naturally are. He wants the position of our heart moved. He wants it shifted to the right.
Changing our natural negative traits can be hard. It can take time. The Psalmist indicates that our hearts must be broken (Psalm 34:18) and created anew (Psalm 51:10). The procedure is done to us (Ezekiel 36:26). We cannot make the change by ourselves.
A heart shift is a procedure we have to want. The Word of God is one of the instruments used to do it (Psalm 119:11) and prayer is another (Psalm 139:23–24). The procedure will make us different. It will cause us some pain. But the outcome, a shifted heart, is what God desires for us.