The present dissertation examines the function and nature of the heavenly sanctuary/temple and its relationship to the earthly counterparts in the major passages of the New Testament (NT) Gospels, Acts, Pauline and General Epistles where the sanctuary/temple motif is found (a total of twenty-two passages). After the introductory chapter, chapters 2, 3, and 4 are devoted to the exegetical analysis of these major passages following canonical order and divisions of the NT. This exegetical analysis has detected the relevance of the heavenly sanctuary/temple motif for NT studies, i.e., how its function, nature, and relationship to the earthly counterparts influence the understanding of important themes of the NT such as salvation, intercession, spiritual gifts, love, holiness, eradication of evil, among others. This investigation has identified that the heavenly sanctuary/temple in the NT function as God’s dwelling place. It is a place for reunion, reconciliation, and sending of the Holy Spirit, from where every spiritual blessing is bestowed upon the believers. In the heavenly sanctuary/temple Jesus is enthroned to exercise authority, power, sovereignty, and rulership; it is where judgment and vindication are made, the new covenant is ratified. It is a place to present praise and worship to God, celebrating Christ's victory over evil. The heavenly sanctuary/temple is where Christ presents His once-for-all sacrifice, "obtains eternal redemption," and intercedes in our behalf, giving assurance that God's salvific purpose and the heirs' hope will be fulfilled. The heavenly sanctuary/temple also functions as the motivation and ground for holy living, the driving force for sacrificial service and endurance of suffering for Christ. The heavenly sanctuary/temple is also the final destination of the Christian journey where all believers will gather together with the godhead and the angels in a festal assembly. Regarding the nature of the heavenly sanctuary/temple in the NT, the passages surveyed show that architecture is not the main concern of the NT writers. However, in tune with the Old Testament (OT), they describe the heavenly sanctuary/temple in terms of a spatiotemporal reality where the corporeal resurrected Jesus is at work and the bodily resurrected believers will live. This NT ontological perspective safeguards the actuality of the heavenly sanctuary/temple many functions. The spatiotemporal nature of the heavenly sanctuary/temple is strengthened when one looks at its relationship to the earthly counterparts. The NT passages examined demonstrate that there is structural and functional correspondence between OT and NT heavenly and earthly counterparts within a typological framework, as well as dynamic interaction among them. Chapter 5 offers a theological synthesis of the heavenly sanctuary/temple motif presented in the previous chapters. A summary of the findings is first provided followed by inferences of theological implications in the three main areas of this dissertation (function, nature, and relationship). After these concluding remarks, an appendix is provided with a brief treatment of twenty-five NT passages not dealt with in the main text (including thirteen passages in the book of Revelation) in order to give the reader a more comprehensive perspective of the pervasiveness of the heavenly sanctuary/temple motif in the NT. In conclusion, the study of the heavenly sanctuary/temple motif in the NT seems to be needed in order to have a sound and balanced understanding of NT theology.