To testify the Truth and to prove falsehood as false; even though It is hateful for the Mujirims.
Battle of Bad’r was the first battle that happened to differentiate the Truth from the falsehood. The Mujirims mentioned in this verse were the Meccan Pagans since they were knowingly rejecting verses which were revealed in their language. When the propagation of Islam was not possible at Mecca, Messenger and believers migrated to Medina. The Book was not codified during that time.
Today, Adhikr—the Truth—is formed as a Book. Whoever from the hypocrites and their followers mentioned in verses 48: 6 and 98: 6 don’t testify It, they are following falsehood and all their deeds will be perished. As mentioned in verses 7: 8-9. These Mujirims mentioned in 52 places in the Book are serving Satan without utilizing their intelligence as explained in verses 6: 55 and 7: 40. It is told in verses 17: 81 and 34: 49: “Truth has come and falsehood has perished; indeed, falsehood has to perish”. Verses 3: 101 and 4: 175 end as: “Whoever holdfasts Allah, then he is guided into the Straightpath”. To holdfast, Allah means to holdfast Adhikr—which is the Straightpath mentioned in 35 places—as explained in verses 2: 256 and 5: 48. See explanation 2: 119, 147; 6: 91 and 153.