One of the benefits of the New Covenant is the placement of the Law within the Believer by writing it on his heart (Jer 31:33; Isa 59:21; Heb 8:10; 10:16). But what is this Law and what does it mean "writing it on his heart"?

The Law is in reference to the Law of Moses. Many scholars understand "writing it on the heart" as a figure of speech symbolic of the internal nature of the covenant (in contrast to the stone tablets of the Law) that would cause a change in the will, heart and conscious of the Believer.

This provision of the New Covenant provides access to spiritual wisdom that was never before available to a non-Believer (1 Cor 2:7-9).

And while the Jews’ practice of the Mosaic Law failed in its demand for holiness, Jesus reveals the true intent and practice behind the legislation (Matt 5:17-48). In broadening the concept of sin, holiness approach heights of impossibility and God defies comprehension. Against this background, the assurance of the forgiveness of sins provided by the New Covenant displays a love beyond human understanding and provides a basis for a Believer’s motive to be obedient to God.

Unique to Christianity is the concept of regeneration (Ezek 36:25-28; Tit 3:5), where the triune nature of God coexists within the Believer. This spiritual union defines the personal relationship between God and the Believer and serves a specific purpose in the New Covenant; it provides the supernatural means to cause Believers to live in a holy manner (Ezek 36:25-28).

The Believer is in God the Father (John 17:20-21; 1 John 2:23-24; 4:15-16; 5:19-20), and the Father is within the Believer (John 14:23).

While God the Father is committed to love and to benefit the Believer, His holy character has no tolerance for sin (Jer 32:39-40). Be holy, because God is holy (Matt 5:48; 1 Pet 1:15-16).

The Believer is in God the Son (2 Cor 5:17; Col 1:27). and the Son is within the Believer (John 14:19-20; 15:5; Gal 2:19-20).

For His willing sacrifice for the atonement of mankind’s sin, Jesus provided freedom from the ruling power of sin (John 8:31-33; Rom 6:11-18).

The Holy Spirit is in the Believer (Rom 8:9-11; 1 Cor 3:16; 6:19; 2 Tim 1:14).

Among It’s primary and divine purpose, the Holy Spirit was given to help the Believer learn the truth and understand the Bible (John 14:16-17, 26; 1 Cor 2:10-16).

Thus before a Believer makes any effort of sanctification, the New Covenant has accomplished what God intended by blessing the Believer with access to spiritual wisdom and motivation to be a holy people; an unconditional covenant that a Believer cannot break (Jer 31:31-33). This enables the Believer to sanctify himself, separate himself from the profane, and devote and dedicate himself to God in the following manner:

1. Sanctify his mind. With the help of the Holy Spirit in learning the truth about Jesus and understanding the Bible, one reappraises the facts of life and worldview perspective (Rom 12:2; Col 1:9-10; 3:9-11; Philip 1:9; 2 Cor 10:4-5; Eph 4:17-24).

2. Sanctify his will. With the spiritual union of the Trinity, one’s purpose in life is altered (Philip 2:12-13; 2 Cor 7:1).

3. Sanctify his character. In cooperating with the Holy Spirit, one produces the fruit of the Spirit (Gal 5:22; 1 John 2:29; 3:9-10).

4. Sanctify his body. In recognition of sanctification through the forgiveness of sin and the consecration by the indwelling of the Holy Spirit, one learns about the sanctity of his human body (1 Cor 3:16; 6:15-20; 9:27; Rom 6:12).

However this process of sanctification is determined to the extent of one’s efforts of cooperating with the Holy Spirit. It requires the Believer’s effort in (Rom 12:1-2):

Bible Study and Reflection: Bible study is a personal responsibility to deepen one’s relationship with God (John 14:21), live as His people (Ps 1:1-3; Matt 4:4; John 17:17; Col 3:16) and discern good from evil (Heb 5:14; Philip 4:8).

Prayer and Worship: Prayer and worship is a personal responsibility to communicate with God in praise and thanksgiving (Eph 6:18; Philip 4:6; Eph 5:18-20).

Continual Self Improvement: The process of sanctification is a personal responsibility to run from the "old" self to the "new" without stopping or looking back (Rom 6:5-7; Col 3:9-10; 2 Cor 3:12-18; Philip 3:10-16; Heb 12:1-14).

Christian Fellowship: Christian fellowship is a personal responsibility towards other Believers as they have a responsibility towards you (1 Cor 12:12-26; Gal 6:1-2; Eph 4:1-16; Heb 10:24-25; 1 Thess 5:11) in serving God together (1 Pet 1:13-14; 2:5-9).

When one is diligent in the process of sanctification, it eliminates a Believer’s vulnerability to the desires of his sinful nature (Gal 5:16-18), which Paul calls "liberty" and the Fruit of Spirit is the natural result (Gal 5:21-23). Along the way, God may employ discipline or trials in the process (Heb 12:4-15). When a Believer fails in their personal responsibility of sanctification, sin prevents fellowship with God and destroys fellowship with other Believers. But one can recover and resume the process of sanctification with repentance (1 John 1:9; Gal 5:7-21).

While sanctification benefits the Believer with joy and peace (Rom 14:17; Gal 5:22), it serves in the work of God by initiating the recovery of the image of God (Eph 4:24), testifies to the love of God (John 13:34-35) and testifies to the reality of Jesus Christ (John 15:26-27; 17:20-21; 6:29).