“Then Peter said to them, “Repent, and let every one of you be baptised in the name of Jesus Christ for the remission of sins; and you shall receive the gift of the Holy Spirit.” Acts 2:38 (NKJV)
Repentance: Jesus appointed Paul saying “I will deliver you from the Jewish people, as well as from the Gentiles, to whom I now send you, to open their eyes, in order to turn them from darkness to light, and from the power of Satan to God, that they may receive forgiveness of sins and an inheritance among those who are sanctified by faith in Me.’” Acts 26:17-18 (NKJV) This means changing your mind or renewing your mind and be transformed. This change should be a right about turn because the worldly way is directly opposite to Godly ways- darkness to light and power of Satan to power of God. You have to renounce your old walk and start walking anew with Jesus.
Baptism: Jesus said, “Go into all the world and preach the gospel to every creature. He who believes and is baptised will be saved; but he who does not believe will be condemned.” Mark 16:15-16 (NKJV) This baptism is not the one given to a new born child like in many churches do. A child will not understand anything and so cannot believe and get saved. So the one takes the water baptism should be of age to know why they take and believe in the finished work of the Lord Jesus Christ for them. And Jesus is saying if you do not believe and take baptism you are already condemned.
Holy Spirit Anointing: Jesus said, “You shall receive power when the Holy Spirit has come upon you; and you shall be witnesses to Me in Jerusalem, and in all Judea and Samaria, and to the end of the earth.”” Acts 1:8 (NKJV) You get power when you receive the Holy Spirit to do the work, this the Lord Jesus Christ asked everyone who believes in Him to do. This is our responsibility to get the anointing of the Holy Spirit to have holy and powerful life and to preach to as many as possible.
These are the basic requirements of a person who calls himself or herself a Christian. The Lord Jesus had set us an example of how to operate in the gifts of the Holy Spirit and the Apostles also, who followed Jesus, did the works as Jesus did and have given a lot of teachings and illustrations for us to follow.
“Jesus said to them, “My food is to do the will of Him who sent Me, and to finish His work. Do you not say, ‘There are still four months and then comes the harvest’? Behold, I say to you, lift up your eyes and look at the fields, for they are already white for harvest! And he who reaps receives wages, and gathers fruit for eternal life, that both he who sows and he who reaps may rejoice together.” John 4:34-36 (NKJV)