There are three reasons why Jesus wants to baptise us in the Holy Spirit (Acts 1:4-5, 8):

(1) Spirit baptism greatly impacts our personal relationship with God (Acts 2:4). At conversion, we have the indwelling of the Spirit. Now, we have the infilling of the Spirit. Jesus fully immerses us into the Spirit of God, until we are filled, thoroughly soaked, saturated, drenched, and overwhelmed by the Spirit.

(2) Spirit baptism greatly impacts our relationship with other believers (1 Cor 12:7-11). We are now empowered to minister and edify one another, especially in the nine supernatural charismatic gifts:
(a) Word of wisdom
(b) Word of knowledge
(c) Gift of faith
(d) Gifts of healings
(e) Workings of miracles
(f) Discerning of spirits
(g) Prophecy
(h) Speaking in tongues
(i) Interpretation of tongues

(3) Spirit baptism greatly impacts our witness of Christ to the world (Acts 1:8).