II Peter 1:19
We have also a more sure word of prophecy; whereunto ye do well that ye take heed, as unto a light that shineth in a dark place, until the day dawn, and the day star arise in your hearts.
Jesus Christ is the “DAY STAR.” “I am the root and the offspring of David, and the bright and morning star.” (Rev. 22:16) The reality of Christ’s arising in the heart by His Spirit, giving full assurance, creates a spiritual fullness in the heart. This is associated with the coming of the Day of the Lord, as being the earnest or assurance of it, although our hearts shall not fully realize Christ in all the unspeakable glory of His body presence, until He shall come.