What is the way to overcome a relapse for a student of knowledge?

If the relapse is related to faith, its remedy lies in strengthening one's faith. If it is a slackening in the pursuit of knowledge, one is advised to study the virtues of knowledge and scholars, especially Ibn Al-Qayyim's book "Miftah Dar As-Sa'adah" (Key to the Abode of Happiness).

A Muslim must remain steadfast upon Allah's command throughout their life. The greatest causes of steadfastness are fulfilling the commands of Allah and His Messenger, as stated in the Almighty's saying: "Allah keeps firm those who believe, with the firm word, in worldly life and in the Hereafter," and His saying: "And if they had done what they were admonished thereby to do, it would have been better for them and a stronger confirmation [of faith]."

Furthermore, righteous companionship aids in obedience to Allah, as per the Almighty's saying: "O you who have believed, fear Allah and be with the truthful."