Jesus never makes the claim that he was God because he was not God.
There are many scriptures that show this. Look at John 17: 3-5 for example, it reads: “This means everlasting life, their coming to know you, the only true God, and the one whom you sent, Jesus Christ. 4 I have glorified you on the earth, having finished the work you have given me to do. 5 So now, Father, glorify me at your side with the glory that I had alongside you before the world was.
It is true that at John 10:30 Jesus says that he and the father our one but what did he mean? In verse 33 the Jews are going to stone him because they (the Jews) claim that Jesus is making himself God. But is he? If you keep reading until verse 36 Jesus says: “do you say to me whom the Father sanctified and sent into the world, ‘You blaspheme,’ because I said, ‘I am God’s Son’?” So it was not Jesus who was claiming to be God, it was the Jews who claimed that Jesus was claiming to be God, Jesus plainly shows that he was claiming to be God's son, not God.
So, why did Jesus say that he and the father were one (vs 30)? This can be answered by going back to chapter 17 of John, it is good to read the whole chapter to get the point completely, but starting at vs 20 it reads: “I make request, not concerning these only, but also concerning those putting faith in me through their word, 21 so that they may all be one, just as you, Father, are in union with me and I am in union with you, that they also may be in union with us, so that the world may believe that you sent me. 22 I have given them the glory that you have given me, in order that they may be one just as we are one. 23 I in union with them and you in union with me, in order that they may be perfected into one, so that the world may know that you sent me and that you loved them just as you loved me.”
You might want to look at John 20:17, where Jesus is talking to Mary and he plainly shows that he is not God: “Jesus said to her: “Stop clinging to me, for I have not yet ascended to the Father. But go to my brothers and say to them, ‘I am ascending to my Father and your Father and to my God and your God.’”
Also, see Revelation chapter 3 where Jesus, now back in heaven, says to those who conquer: “‘The one who conquers—I will make him a pillar in the temple of my God, and he will by no means go out from it anymore, and I will write upon him the name of my God and the name of the city of my God, the New Jerusalem that descends out of heaven from my God, and my own new name.