The Creator Himself is so powerful and glorious that He cannot be approached in person by human beings. He alone "hath immortality, dwelling in the light which no man can approach unto: whom no man hath seen, nor can see (1 Timothy 6:16). Angels do not have man's shortcomings, and can therefore act for God and represent Him when communicating with men and women. They bridge the huge gap between the holiness and perfection of God in heaven and the shortcomings of dying people on this planet. Angels were made immortal (that is, never to die). Their eternal quality was spoken of by Jesus when he said:
"They which shall be accounted worthy to obtain that world, and the resurrection from the dead, neither marry, nor are given in marriage: neither can they die any more: for they are equal unto the angels; and are the children of God. being the children of the resurrection." (Luke 20:35.36)
Jesus was saying that, in the same way as the angels (the children or "sons" of God) live for ever and are of one gender, so those who will be called the "sons" and "daughters" of God when Jesus returns will also live for ever.