Almost as an Old Covenant Great Commission, Moses explains to the people of Israel what is required of them in response to God’s giving of the Law. Their response is to be obedience with all of their heart:
Deut 26:16, “This day the LORD your God commands you to observe these statutes and judgments; therefore you shall be careful to observe them with all your heart and with all your soul.”
There is a clear link with the second verse in Matthew’s Great Commission, where Jesus commanded His disciples to observe all things that He commanded them and to make that the focus of their teaching ministry:
Matt 28:20, “‘teaching them to observe all things that I have commanded you; and lo, I am with you always, even to the end of the age.’ Amen.”
The idea of “the whole heart” or “all the heart,” as found in Deuteronomy 26:16, is used to described the love that is due God from mankind in Deuteronomy 6:5. Jesus quoted this same verse in Matthew 22 and Mark 12 in response to the question about the greatest commandment in the Law of Moses. Also, a certain lawyer quoted Deuteronomy 6:5 in Luke 10 to describe the Old Covenant approach for gaining eternal life. These three verses also contain “the whole heart” language of Deuteronomy 6:5.
However, in Acts we find a fourth New Testament use of “all your heart.” It is used in the context of a conversation between the Evangelist Philip with the Ethiopian Eunuch. Rather than emphasizing a complete obedience as in Deut 26:16, and rather than a complete emotional commitment to God as in Deut 6:5, Acts 8:37 emphasizes salvation by faith alone:
Acts 8:37, “Then Philip said, ‘If you believe with all your heart, you may.’ And he answered and said, ‘I believe that Jesus Christ is the Son of God.’”
So, in Acts 8:37 we find believing with “all of your heart” as the cornerstone of salvation. And further, the locus of that faith is the person and work of Jesus Christ.
So as the only verbal formula for baptism in the New Testament, Acts 8:37 includes several remarkable concepts:
- The baptismal candidate taking the initiative to request baptism (Acts 8:36);
- The evangelist requiring a belief with all the heart prior to baptizing;
- The baptismal candidate verbally stating in his own words what it is that he believes.
And upon this simple profession of faith, Philip baptized the Ethiopian Eunuch.
So, as Deuteronomy 26:16 is compared to Acts 8:37, there seems to be a remarkable shift in what is required for salvation. This change is made manifest as one from obeying the commandments of God to that of volitionally and emotionally fully believing in Jesus.