In Acts 1 the eleven Apostles, prior to the day of Pentecost, were talking about Judas; the one who betrayed the Lord. They had decided to cast lots between two men; Joseph and Matthias. They knew from scripture that Judas was to be replaced, so they had decided between themselves to cast lots for these two men and prayed that the Lord would decide which one of them He wanted to be the replacement for Judas as one of the twelve Apostles.
I see this as men trying by their own effort to affect the things of God. The Apostles were chosen by the Lord Himself, He did not need any suggestions from man; the Apostles are His chosen witnesses into the world of the things which they have seen and heard.
On the road to Damascus in Acts chapter 9 the Lord Himself chooses the replacement for Judas; a very unlikely character, a man that no one would have guessed; Saul, the persecutor of the brethren who would then be called Paul, used by the Lord to spread the gospel into the outer part of the earth, writing the majority of the epistles in the New Testament.
A slave of Jesus Christ