I believe "baptisms" can also have, at least in part, reference to "the threefold baptism of spirit, blood, and water, which have some agreement with each other" -JG (1 John 5:6, 8). The idea is not to remain at the point of rebirth but to "go on unto maturity" (Heb 6:1). There are those who are content with just being saved without growing in it.
Yes sir.
The power and Grace to mature comes from being a partaker of His Divine Nature through the exceedingly precious promises.
as His divine power has given to us all things that pertain to life and godliness, through the knowledge of Him who called us by glory and virtue, 4 by which have been given to us exceedingly great and precious promises, that through these you may be partakers of the divine nature, having escaped the corruption that is in the world through lust. 2 Peter 2:3-4
One of which is the promise of The Father. The Holy Spirit.
JLB