What does a student of knowledge favor if the evidence is equal in a controversial jurisprudential issue, such as the issue of the disbelief of one who abandons prayer? And what does he do if there is a slight preference for one of the opinions?

If the evidence is equally balanced for a student of knowledge or a mujtahid (independent jurist) and he finds no preponderant factor, then he may follow (taqlid) someone whose knowledge and religiosity he trusts, as mentioned by Sheikh al-Islam Ibn Taymiyyah, and the obligation of ijtihad (independent reasoning) falls away from him. If the trustworthy people of taqlid (those who are followed) differ, it is said that one should adopt the stricter opinion, and it is also said that one may adopt any of the opinions he wishes, as long as he does not intend to merely seek out concessions. Another opinion is that one should adopt the easier opinion, which is what Sheikh Ibn Uthaymeen preferred. The best and most cautious approach in this dubious matter is to act according to the opinion that provides a safeguard for the religion.