What is the ruling on befriending someone whose disbelief is uncertain? And what is the ruling on befriending the followers of deviant sects?

"Whoever's Islam has been established with certainty, their Islam does not cease by doubt. Nor is a judgment of apostasy issued against them except after establishing what necessitates it, presenting the evidence against them, and fulfilling the conditions of declaring someone an apostate while precluding any impediments. If their apostasy is established with certainty, the ruler must apply the penalty for apostasy upon them if they do not repent. If the ruler does not apply the penalty, then boycotting and showing enmity towards them becomes obligatory, as an expression of hatred for their sake in Allah. Companionship and affection with them are not permissible. This also applies to the people of deviant sects who persist in their error after being called to the truth; boycotting them is legislated, and it may become obligatory if it is the determined means for their reform, this being to rebuke and discipline them."