The seriousness of this question for Pentecostalism is that Ephesians 4:5 makes "one baptism" the basis of the unity of the church. Pentecostalism, on the other hand, has a church is which some have only the first baptism, while others have also the second baptism, which is supposed to bestow on them more wonderful experience and much greater power.
Lumilitaw tuloy ang tanong kung bakit sinabi ni Pablo sa Efeso 4:5 na ang Iglesiya ay may iisang bautismo? Kaya naman mahalaga ang isyu na ito para sa Pentecostalismo ay dahil ayon sa Efesa 4:5 ang pagkakaroon ng iisang bautismo ang siyang saligan ng pagkakaisa ng Iglesiya.