There are many baptisms in the Bible, but there is only ONE baptism today and it is BY ONE SPIRIT into ONE BODY (not "of the Holy Ghost" and not "by man into the water" ) .

1 Corinthians 12:13 KJV For by one Spirit are we all baptized into one body, whether we be Jews or Gentiles, whether we be bond or free; and have been all made to drink into one Spirit.

When one trusts the Lord after hearing and believing the word of truth (1 Corinthians 15:1-4 KJV) they are baptized by one Spirit in to one Body (1 Corinthians 12:13 KJV).

It is a baptism (identification) into Christ's death,

Romans 6:3-5 KJV Know ye not, that so many of us as were baptized into Jesus Christ were baptized into his death? 4 Therefore we are buried with him by baptism into death: that like as Christ was raised up from the dead by the glory of the Father, even so we also should walk in newness of life. 5 For if we have been planted together in the likeness of his death, we shall be also in the likeness of his resurrection:

It's a Spirit baptism into Christ,

Galatians 3:27 KJV For as many of you as have been baptized into Christ have put on Christ.

It is the one baptism of Ephesians 4 that we are to endevour to keep.

Ephesians 4:1-6 KJV I therefore, the prisoner of the Lord, beseech you that ye walk worthy of the vocation wherewith ye are called, 2 With all lowliness and meekness, with longsuffering, forbearing one another in love; 3 Endeavouring to keep the unity of the Spirit in the bond of peace. 4 There is one body, and one Spirit, even as ye are called in one hope of your calling; 5 One Lord, one faith, one baptism, 6 One God and Father of all, who is above all, and through all, and in you all.