A Promise of Rest

There is a lot of restlessness in the world today. And in the Gospel is a message of rest. We need rest and it's found in the New Covenant. Here's what the writer of Hebrews writes: "Therefore, since the promise of entering his rest still stands, let us be careful that none of you be found to have fallen short of it." Hebrews 4:1 A listener asks for clarification concerning a Christian committing suicide.Why is there such a huge difference in the tone of the letters of some books of the Old Testament?As a learning pastor, I want to know the best way to explain the passages in Acts concerning believers receiving the Holy Spirit after they believed.