The heart, as understood in Scripture, represents the core of our being, encompassing our thoughts, emotions, and actions. It is the seat of life and the essence of who we are, directing our conduct and reflecting our innermost feelings. When considering a circumcised heart, it signifies a spiritual transformation, a preparation of the heart to serve God with complete obedience and devotion. This involves setting the heart aright through repentance, study, and diligent effort to align with God's laws and intents. Preparing the heart to serve God requires a deliberate plan to overcome personal failings and societal influences that draw us away from Him. It means to labor in service, to become a servant of Jesus Christ, focusing on obedience in every aspect of life. God looks upon the heart, seeking a genuine change in our nature to reflect His own. He desires a heart that is fully exposed to Him, unable to hide any thought or intention, and committed to faithfulness rather than mere outward acts of sacrifice. The call to prepare our hearts echoes through the ages, urging each individual to repent deeply, to study God's Word with diligence, and to apply His teachings in daily life. This preparation is not a collective endeavor but a personal responsibility, ensuring that our relationship with God is right. As we set our hearts to serve Him alone, we develop godly character through consistent obedience, prayer, fasting, and study, transforming our lives into a joyous and liberating experience of working alongside God. God promises a new heart and spirit to His people, enabling them to obey Him fully. For those called, this new heart is a precious gift that must be nurtured through faithful service and overcoming. Trials and tests are designed by God to refine our hearts, preparing us for salvation. As we trust in His faithfulness during these challenges, we must respond with a faithful heart, serving Him with love and adherence to all His laws, thus readying ourselves to receive the salvation He offers.

The concept of a circumcised heart is central to understanding the spiritual transformation required under the New Covenant with God. A circumcised heart is one that is open, pliable, and amenable to the Word of God, yielding to His will and submitting to His guidance. In contrast, an uncircumcised heart is closed and resistant, impervious to God's attempts to influence it, often characterized by a stiff-necked, unyielding attitude. God uses circumcision as a symbol of what must happen to a person's heart under the New Covenant, looking far beyond the physical act to its spiritual ramifications. Spiritual circumcision is a cooperative effort where God performs a supernatural circumcision, breaking the shackles of the adversary and enabling a person to yield and subdue human nature's resistance. Simultaneously, individuals must take responsibility to submit and make choices aligned with God's will. Circumcision, in this spiritual context, is defined as keeping the law consistently, not as an occasional act but as a way of life. Uncircumcision is marked by consistent law-breaking, reflecting a heart that has not been transformed. True circumcision is not merely an external mark but a quality of mind revealed in how one lives, demonstrating obedience from a yielded heart. Those who are truly circumcised worship God in spirit, guided by His Spirit and possessing its qualities, ensuring that their worship is from the inside out. They glory in Christ, recognizing salvation through Him and His righteousness, understanding that works do not save but serve a different purpose. They also have no confidence in the flesh, acknowledging that human accomplishments, no matter how significant, are fleeting before God, and thus they rely on Christ's righteousness without pride or boasting. The ongoing process of conversion involves both God's supernatural circumcision of the heart and the individual's continual effort to yield and align with His will. This transformation changes one's perspective and worldview, ensuring that obedience to rites and ceremonies is grounded in love for God and service to others. The life of a person with a circumcised heart becomes a transparent testimony, broadcasting a change in mind and behavior that others can notice, reflecting the inward reality of God's work.

Circumcision of the heart, as distinct from physical circumcision, signifies a profound spiritual repentance and conversion that deeply affects the mind, character, and conduct. It is an inward transformation, done to the heart itself, marking a significant shift from mere external observance to internal change. In the context of the broader discussion, this spiritual circumcision contrasts with the physical act or the theology surrounding it, which was deemed not necessary for spiritual salvation by the council in Acts 15. The emphasis on heart circumcision underscores its role in aligning one's life with the spiritual intent of God's laws, far beyond the outward rituals or the burdensome regulations added by human tradition. This inward change is essential for a true relationship with God, highlighting that external rites, while significant in the Old Covenant as signs and seals, hold no effect on spiritual holiness under the New Covenant if they do not penetrate the heart. Keeping the commandments, which enters into the heart, is presented as everything in comparison to the external act of circumcision, which is of no spiritual value without this deeper transformation.