The New Testament says much about purity of heart. It is looked for as the true practical condition of all Christians, though, alas we are not all “pure in heart.” We say so much, and truly, about the deceitfulness of the human heart that the expression “pure in heart” is supposed, even by most Christians, to be only a figure of speech or a doctrinal standing. But Scripture means a great deal that is most definite and practical by purity of heart. Paul says, “Follow righteousness, faith, charity, peace, with them that call on the Lord out of a pure heart” (2 Timothy 2:22). Peter speaks of the Gentiles as “purifying their hearts by faith” (Acts 15:9), and in his epistle he says, “Seeing ye have purified your souls in obeying the truth … love one another with a pure heart fervently” (1 Peter 1:22). James adds, “Purify your hearts, ye double minded” (James 4:8). John, in speaking of the Lord’s coming, says, “And every man that hath this hope in Him purifieth himself, even as He is pure” (1 John 3:3).
To be pure, the heart must have an object that is absolute in purity. Thus, as the Lord Jesus is the object of our undivided hearts, we will find that we are progressively “changed into the same image” (2 Corinthians 3:18) and that our hearts, as polished mirrors, will reflect His glory.