Yes, Jesus is God. The Bible, in the Great Shema, teaches us that there is only one God and that is YHWH. The Bible also teaches us that the man Jesus is Christ and YHWH, which we receive as a holy mystery by faith. That is, how can God who is infinite dwell in that which is finite? According to reason, it shouldn't be possible, but God is greater than our reason. So Jesus is 100% man and 100% God, He is fully man and fully God, God in flesh.
Any religious body that believes and teaches that Jesus is not God is not Christian. The divinity of Christ is absolutely central to the Christian faith, and this is formally confessed by all Christian church bodies, including the Eastern Orthodox, Roman Catholic, Lutheran, Anglican, Reformed, Methodist, Baptist, and most Charismatic, Pentecostal, and non-denominational churches. There are theologically liberal people in many traditions who may deny the divinity of Christ, but they're not in line with their respective confession of faith or the Scriptures.