Taking a Pledge From the Prophets to Believe in Our Prophet, Muhammad ﷺ

Allah states that He took a pledge from every Prophet whom He sent from Adam until `Isa, that when Allah gives them the Book and the Hikmah, thus acquiring whatever high grades they deserve, then a Messenger came afterwards, they would believe in and support him. Even though Allah has given the Prophets the knowledge and the prophethood, this fact should not make them refrain from following and supporting the Prophet who comes after them. This is why Allah, the Most High, Most Honored, said

وَإِذْ أَخَذَ اللَّهُ مِيثَـقَ النَّبِيِّيْنَ لَمَآ ءَاتَيْتُكُم مِّن كِتَـبٍ وَحِكْمَةٍ

The infallibility of the Prophets

The verse implies that a person whom Allah invests with the Book, the Wisdom and the power of making decisions, and places him on the great station of prophethood is always faithful to his mission when he communicates the Divine message to people and calls on them to be-come His faithful servants. That he starts moving people away from the worship of only one God and starts asking them to become his own worshippers or the worshippers of some other creatures is something he can never do. If so, this would mean that the one whom Allah had sent as his messenger did not, in fact, deserve this designation. Any government of this world, when appointing someone to an office of responsibility, always takes two factors into consideration: