Baptism as myself understands is a NT ordinance, and at the same time an act of worship. Christ Jesus the Lord has said worship must be in Spirit and in Truth. Coupling this to the ordinance of baptism means that the administration of the ordinance, on part of the administrator, must be in Spirit and in Truth. And on part of the candidate or receiver of baptism applies the same, it must be received or submitted to in Spirit and in Truth. All else is sin, because not out of faith. Thus the candidate must be a genuinely converted person, and he must seek baptism from the right motive(s).
The administrator must have proper authority to administer baptism, and he must administer it only to a genuine convert according to the NT model, which is by immersion in water. For the administrator to be fit to administer true Gospel baptism he must be a male member of a true NT assembly of Christ, and must be authorized by the assembly he belongs to to administer baptism. I think most Baptists have held that the administrator must be an ordained minister of the Gospel.
Immersion at the hand of an apostate religious body is alien baptism, null and void, because of the lack of proper authority. Such an immersion myself had many years ago at the hands of an arminian Baptist assembly that was moderately charismatic. It was null and void, but I learnt it a bit too late, nevertheless I count it dung today. It was not worship, although I trust myself to have been a genuine convert back then, but participating in an act of idolatry with a flock of Christ-deniers.
True Gospel baptism is a holy ordinance, and it must take place in Spirit and in truth, with a God-given right motive and according to Scripture guidelines, for it to be worship as the word of God defines worship. Whatever is not out of a law of faith is sin and transgression of the law. Not all "Baptist baptism" is true baptism, most is alien immersion.
Harald