ELDERS WHO ARE ABLE
Elders are responsible for making sure that those who desire to be immersed in water understand what it is. Misunderstandings and ideas can be held that are unscriptural and may be held unwittingly.
No one should be immersed to help them overcome spiritual problems or to help with personal needs, etc.
Someone might need to be asked if they are asking of their own free will? Are others being immersed or because someone has told them they should.
Perhaps someone who has grown up among Believers may feel they deserve to be immersed.
Above all, no one should have the idea that being immersed in water saves them.
The presence of Elders overseeing immersions can make all the difference, especially when the Holy Spirit moves in giving gifts and blessings.
As in Acts 19'1-6. When Paul had immersed some Disciples "... he laid hands on them, the Holy Spirit came upon them, and they spoke with tongues and prophesied".
When John immersed Jesus, he could surely only stand and watch in amazement at what he was seeing:
"When He had been immersed, Jesus came up immediately from the water; and behold, the heavens were opened to Him, and He saw the Spirit of God descending like a dove and alighting upon Him.
And suddenly a voice came from heaven, saying, 'This is My beloved Son, in whom I am well pleased'," Matthew 3'16-17.
Elders who are able to act in harmony with the moving of the Holy Spirit during an immersion make a difference for the person Believer immersed.