... He (Jesus) was lifted up and a cloud took him out of their sight.
The Ascension of the Lord Jesus Christ. Perhaps we don't take as much notice of the ascension of Jesus as we should. We all love the story of the birth of Jesus, and so we should; we thank God for the perfect life of Jesus, and so we should. We are humbled by the sufferings and death of Jesus, and so we should be; and the wonder of the resurrection of Jesus makes us shout, "He is risen indeed. Hallelujah!" Pentecost is the start of glorious things for the Church of Christ and we bless God for that. But all of these wonderful happenings were confined to a small corner of the world, and to one nation of people in particular.
The ascension of the Lord Jesus to heaven and to the very throne of God signals the start of the great worldwide mission of the church of Jesus Christ. Why? Because from heaven Jesus sent his Holy Spirit to give power to the messengers of the Good News of Jesus as they went with his authority to make disciples of all the nations. This work will continue until the Lord Jesus returns in glory to "judge the living and the dead" and to establish all his people in their everlasting heavenly home.
The apostles of Jesus saw him lifted up from them and at first no doubt wondered how they could get on without him. They kept looking at the empty sky until the heavenly messengers assured them that Jesus would return. In the meantime they had plenty of work to do!