Israel, in the singular, is called God’s servant throughout the Bible, for e.g. Isa. 45:4; 48:20; 49:3; Jer. 30:10. Also, note that in Jer. 30:17, the servant Israel is regarded by the nations as an outcast, forsaken by God, as in Isa. 53:4; Jer. 46:27-28; Ps. 136:22, a messianic reference. Also, given the Christian view that Jesus is God, is God His own servant? What’s your response?
The Jewish idea of God’s servant in the Old Testament, especially in Isaiah, is complex. It is used of Israel itself, but also of the Messiah. For example, in Isaiah 44:1, God’s servant is Israel–it is God’s chosen people. But then in Isaiah 42:1, God’s servant is clearly a single person. It is the Messiah. There are several examples of God’s servant being Israel in Isaiah, such as Isaiah 42:19 and Isaiah 49:3, but also several examples where the servant of God is the Messiah, such as Isaiah 52:13 and 53:4. I believe that God uses the mixed metaphor of God’s servant both of Israel and of the Messiah for a reason, to make a point. A key passage to understand this is Isaiah 49. In this chapter we are told that because of unfaithfulness, God’s servant will no longer be Israel, but the Messiah. In Is 49:3 he reminds them that he had called Israel his servant. But then in Isaiah 49:4 he explains why he is rejecting them as his servant. This is followed by Isaiah 49:5 and following in which God tells his people that his Messiah will “be my servant.” This is like Ezekiel 34 in which God rejects Israel’s shepherds but instead make the Messiah his true shepherd.
Yes, the Messiah is God’s servant. And, of course, Jesus is the Messiah. Jesus is God (John 1:1,14,18). Therefore, in a sense, God is God’s servant. If one rejects the idea of trinity, then this does not make sense, but in Christianity and in the Bible in particular, Jesus is with God and he is God (John 1:1). I am sure that this criticism is coming from a Muslim source. Yes, Jesus is God, and Jesus also prays to God. In a sense, God prays to God. The Son prays to the Father and the Father praises the Son, yet they are one and the same God. These critics are not trying to honestly appraise the Old Testament. They are only trying to find dirt and to confuse Christian believers. If someone chooses to reject the biblical teaching that Jesus is God, that is their prerogative, but I suggest you not listen to Muslim critics, as they are not trying to be unbiased, but are trying to win people from the truth of Christianity because, unlike the Bible, with all its evidence of inspiration, the Qur’an does not have such evidence. I suggest you not listen to these people.