The GWTJ shall be at the end of the world when Christ comes again, and the DEAD, those who are never among the righteous shall be judged according to what is written in the books and the book of life! The JSC judges' mankind in the flesh through the gospel proclaimed. The Father and the Son are ONE God.
John 10:30 (KJV) I and my Father are one.
John 5:17 (KJV) But Jesus answered them, My Father worketh hitherto, and I work.
John 5:19-24 (KJV) Then answered Jesus and said unto them, Verily, verily, I say unto you, The Son can do nothing of himself, but what he seeth the Father do: for what things soever he doeth, these also doeth the Son likewise. For the Father loveth the Son, and sheweth him all things that himself doeth: and he will shew him greater works than these, that ye may marvel. For as the Father raiseth up the dead, and quickeneth them; even so the Son quickeneth whom he will. For the Father judgeth no man, but hath committed all judgment unto the Son: That all men should honour the Son, even as they honour the Father. He that honoureth not the Son honoureth not the Father which hath sent him. Verily, verily, I say unto you, He that heareth my word, and believeth on him that sent me, hath everlasting life, and shall not come into condemnation; but is passed from death unto life.
John 3:17-18 (KJV) For God sent not his Son into the world to condemn the world; but that the world through him might be saved. He that believeth on him is not condemned: but he that believeth not is condemned already, because he hath not believed in the name of the only begotten Son of God.
The JSC judges' man in the flesh, what they have done in the body whether good (unto righteousness) or bad (unrighteous) according to how they hear (respond to) the gospel while physically alive. If while in the body of flesh the JSC judges' man to be righteous, they have passed from death to life and at the GWTJ they shall NOT be judged with the DEAD but shall receive the promised inheritance of eternal immortal physical life on the new earth with Christ forever.
2 Corinthians 5:9 (KJV) Wherefore we labour, that, whether present or absent, we may be accepted of him.
2 Corinthians 5:10 (KJV) For we must all appear before the judgment seat of Christ; that every one may receive the things done in his body, according to that he hath done, whether it be good or bad.
Romans 14:8-12 (KJV) For whether we live, we live unto the Lord; and whether we die, we die unto the Lord: whether we live therefore, or die, we are the Lord's. For to this end Christ both died, and rose, and revived, that he might be Lord both of the dead and living. But why dost thou judge thy brother? or why dost thou set at nought thy brother? for we shall all stand before the judgment seat of Christ. For it is written, As I live, saith the Lord, every knee shall bow to me, and every tongue shall confess to God. So then every one of us shall give account of himself to God.
The distinction between the JSC and the GWTJ is the JSC judge's man while they are still physically alive in this world. But the GWTJ shall spiritually judge whether or not man is spiritually alive or is among the spiritually DEAD at the end of this world. When we've gone from death to life before we die, we have this promise that we shall not be judged with the DEAD to be cast into the lake of fire that is the second death.