Matthew 22:32

“I am the God of Abraham, and the God of Isaac, and the God of Jacob? God is not the God of the dead, but of the living.”

He points out that God had stated to Moses that ‘I am the God of Abraham, Isaac and Jacob' (See Exodus 3:6; Exodus 3:15), and that as He is not the God of the dead but of the living, the corollary must be that Abraham, Isaac and Jacob must therefore have been alive at the time when He spoke.

This inference takes in a number of factors which different ones will see in different ways:

1). That God was citing their names as those with whom He was ‘in covenant', and as those to whom He must fulfil His covenant. The argument is thus that as He could not have been ‘in covenant' at the time of Moses with a dead person, and certainly could not fulfil a covenant, which is a two party relationship, with a dead person (compare for example Genesis 12:2 where Abraham's effectiveness is to continue on), they must have all been alive at the time of speaking, that is at the time of Moses, when He was about to fulfil the covenant which He had made with them.

2). That He was declaring Himself to be ‘their God'. But He could not be the God of what was non-existent, because for Him to be their God they must be able to appreciate His Godhood, therefore for Him to be their God they must have been in existence at the time of speaking.

Or to put it another way. The dead do not praise God (Psalms 88:10; Psalms 115:7). He is not their God, and cannot be. So if God can declare Himself to be the God of Abraham, Isaac and Jacob they must in some way be enjoying life, even though they have apparently died, in order to appreciate what He is doing. For He is the God only of the living. Indeed some of the Psalmists also actually revealed such a positive, if vaguely expressed, belief in an afterlife on the same basis, that they could not believe that their positive and glorious relationship with God, which was in such contrast with those whose minds were set on earthly things, could possibly cease on death (e.g. Psalms 16:9; Psalms 17:15; Psalms 23:6; Psalms 49:15; Psalms 73:24, see its whole context; Psalms 139:7; Psalms 139:24).

3). That no one in Jesus' time ever said that God  ‘was'  the God of Abraham, Isaac and Jacob. They always, even the Sadducees said, ‘God is --'. By this they thus implicitly recognised their continual existence in their hearts so that He could be their God.

4) That to suggest that the whole of the past is dead and done with is to contradict the nature of God who brings the past into the present, and bases His actions in the present on that past. How could the living God then allow those who had been so faithful to Him in the past to sink into non-existence? It was because He saw Himself as still accountable to them that He would act as He intended. Death had not ceased His obligation, for it was to be seen that He was still obliged to them.

5) Jesus' argument is based on the faithfulness, reliability and fairness of God. Abraham had not received the promises. But how could a faithful God not ensure that at some point he did receive the promises in return for his faithfulness? And that meant that he must still be alive in order in some way to do so.

It is noteworthy that the Sadducees appear to have at least accepted that they had no reply to His argument. It appealed to men's basic sense of the continuing presence of God, and of His fairness, His faithfulness and His unfailing goodness and loyalty, as well as to the idea that He would not forsake those whom He had so tenderly loved.