[24]. Christians practice polytheism, while Muslims uphold pure monotheism. For this reason, it is permissible to pray in a mosque, but not in a church.
At the same time, Muslims affirm the prophethood of Jesus, recognizing that he was sent to the lost sheep of Israel, whereas the Jews deny him. And just as the Jews reject Jesus, the Christians likewise reject the Prophet Muhammad — even though he is mentioned in the Gospel. Therefore, it is an obligation upon both Jews and Christians to follow God’s final Messenger. To turn away from him is to deny the truth.
Mohammad, God's messenger (ﷺ) said: "By Allāh in Whose Hand my soul is. You will not enter Paradise until you believe (and submit to God), and you will not believe until you love one another".
And this is love: that we walk in obedience to Allah’s Commandments. His command is that you worship none but Him and believe in His messenger, the Prophet Muhammad and follow him, and that you walk in brotherhood and love with one another.