David didn’t have this (New Covenant) type of relationship under the Old Covenant. Therefore, when he was repenting over his sin with Bathsheba and Uriah, he prayed,

“Create in me a clean heart, O God; and renew a right spirit within me. Cast me not away from thy presence; and take not thy holy spirit from me. Restore unto me the joy of thy salvation; and uphold me with thy free spirit” (Ps. 51:10-12).

However, for us as New Testament believers to pray this same prayer would be an insult to what Christ has done for us. God created a new heart in us when we were born again (2 Cor. 5:17) and sealed it with His Holy Spirit so it would never be polluted again (Eph. 1:13). He promised He would never leave us nor forsake us (Heb. 13:5), and His love, joy, and peace are now a permanent part of our born-again spirits (Gal. 5:22). Yet multitudes of New Testament Christians pray and sing the exact opposite of this.

Therefore, most Christians aren’t bold in their relationship with the Lord. They approach the Lord with fear of punishment and rejection. They fear they aren’t worthy and that they haven’t done enough to earn the right to be in His presence. They still believe their relationship with the Lord depends on their performance, and mixing the Old and the New Covenant makes the Word of God void in their lives.

Andrew Wommack

In order not to lose the gift of this beautiful Psalm and many, many others, I simply pray (as inspired by Andrew) “Thank you, dear God, that You already have created in me a clean heart through Jesus and have renewed a right spirit within me.” ……. Then I’m good to go, free of mixing, adding or distorting.