Apostasy is when the people turn away from God. No communication from God, leads people into strange paths marked with tradition and false doctrines. The only thing that keeps people from apostasy is following the revelations of God given to His prophets. A testimony of God's truth is the way to salvation. When tradition overtakes testimony then it is an apostasy. Its as if the telephone line gets cut, and the clarity of the message and will of God gets reduced, distorted and lost in a game of telephone.
The Pharisees and Sadducees who crucified the Savior, were huge fans of tradition, because it meant that they didn't have to be righteous on the inside. With the Lord's demonstration of the cursing of the fig tree for not having fruit, it was an object lesson to those that have the outward appearance of righteousness but show no fruit (Matthew 21). We must offer ourselves to the Lord and He will bless us with fruits of righteousness.
Cain offered fruit to the Lord instead of an animal sacrifice and it was rejected. We have to offer the kind of sacrifice the Lord demands in order to be blessed for it. The Lord demands we offer our whole selves and not just the outward appearance, or it will be rejected and we'll be cursed for mocking the Lord.
