them: i.e. the "image" and "god" of Isaiah 45:20.
there is no God. Note the Figure of speech Pleonasm, by which the same assertion is made in two ways (positive. and negative) for emphasis.
Related Commentaries of Isaiah 45:21
Isaiah 45:21
21 Tell ye, and bring them near; yea, let them take counsel together: who hath declared this from ancient time? who hath told it from that time? have not I the LORD? and there is no God else beside me; a just God and a Saviour; there is none beside me.