The reference to blots and blemishes is taken from Jude 1:12, which is also borrowed from Leviticus. Blemishes and defects made an animal unfit for service (Leviticus 1:3) and also prevented men from serving as priests (Leviticus 21:21). With their teaching and behaviour, the heretics were frustrating the church’s aim of holiness and thus were making the church unfit to be presented as a sacrifice to God (see 2 Peter 3:14).1
13 suffering wrong as the wage for their wrongdoing. They count it pleasure to revel in the daytime. They are blots and blemishes, reveling in their deceptions, while they feast with you.