In Acts 1, the risen Lord Christ presents infallible proofs of his resurrection to the apostles. Then he instructs them concerning what will happen after his ascension, namely, that the Holy Spirit will be poured out upon them at Pentecost. Equipped with the power of the Holy Spirit, the apostles will be witnesses to Christ and will preach the kingdom of God from Jerusalem, Judea, Samaria, and to the ends of the earth.