The old heart is a little slave of Satan, taking his orders, and doing what he wishes. The new heart is a happy little servant of Christ, listening to His orders, and doing what He wishes.
Oh how happy and blessed to have this new heart! All God's own children receive it, for He has said, "I will give them one heart;" that is, all the same new heart. Do you not want to have it too? Then "ask, and you _shall_ receive;" for He hath said, "A new heart also _will_ I give you!"
"Oh for a heart to praise my God, A heart from sin set free! A heart that always feels Thy blood, So freely shed for me.
"A heart resigned, submissive, meek, My dear Redeemer's throne; Where only Christ is heard to speak, Where Jesus reigns alone."
"I will put my Spirit within you."--Ezek. xxxvi. 27.
Many years ago a good clergyman wrote a tiny prayer, so short that no one could help remembering it if they once heard it. God seemed to set that little prayer "upon wheels," so that it might run everywhere. It was printed on large cards and hung up, and it was printed on small ones and kept in Bibles and pocket-books. It was taught to classes and schools and whole congregations, and now thousands upon thousands pray it constantly. It is a prayer which must be heard, because it asks for what God has promised to give; and it asks for this through Him whom the Father heareth always. It is this: "O God, give me Thy Holy Spirit, for Jesus Christ's sake. Amen." Will you not pray it too? Begin this morning, and go on, not just _saying_ it, but _praying_ it, till you get a full answer. For you are quite sure to get it; here is God's own promise, "I _will_ put my Spirit within you;" and He has promised it over and over again in other places. Perhaps you will not know at first when the answer comes. Can you see the dew fall? No one ever saw a single drop come down, and yet as soon as the sun rises, you see that it has come, and is sparkling all over the fields. It came long before you saw it, falling sweetly and silently in the twilight and in the dark. So do not fancy God is not hearing you because you have not felt anything very sudden and wonderful. He is hearing and answering all the time. You would not go on asking unless the dew of His Spirit were already falling upon your heart, and teaching you to pray. The more He gives you of His blessed Spirit, the more you will ask for; and the more you ask, the more He will give.