Hebrews 3

The apostle does not speak of himself as an apostle in Hebrews, because Christ is before us as the Apostle and High Priest of our confession. Here the Lord presents His person and office between God and ourselves.
Christ is seen here, not only as our Apostle and High Priest, but also as Son over God's house. Moses was faithful as over God's house. Christ is more excellent than Moses, because He who built the house has more honor than the house. The house is a figure of all things built by Christ who is God. We are God's house, at least those who hold fast to the end, which every true believer will do.
Three steps to apostasy are given here. The first step is to hear the gospel or read the Word and reject it by hardening the heart. "Harden not your hearts." The second step is, "They do alway err in their heart; and they have not known My ways." The final step is, "An evil heart of unbelief, in departing from the living God."
Judas gives the picture of apostasy. He was a companion of the Lord Jesus, his "own familiar friend." He heard the Word from the lips of the Lord Jesus day by day and rejected it. Then he erred in his heart and became a thief. Finally, Judas had an evil heart of unbelief in departing from the living God.
This path Christendom has taken, not giving heed to the Word, erring in the heart, and with an evil heart of unbelief departing from the living God. Profession is not enough. There must be the continuing unto the end, which the believer will do.
"Today if ye will hear His voice, harden not your hearts, as in the provocation." The provocation was the time when the twelve spies went into Canaan and returned, some with a good report that it was a good land flowing with milk and honey but that there were giants there. Joshua and Caleb said, "Let us go up at once, and possess it; for we are well able to overcome it.... They are bread for us." But the multitude refused it and provoked God.
Because they had hope, the wilderness became a refreshing air to Joshua and Caleb. But God was grieved with those who had sinned; they fell in the wilderness and died. The wilderness proves whether or not there is faith.