Adam Clarke on Colossians 2:12

Buried with him in baptism - Alluding to the immersions practised in the case of adults, wherein the person appeared to be buried under the Water, as Christ was buried in the heart of the earth. His rising again the third any, and their emerging from the water, was an emblem of the resurrection of the body; and, in them, of a total change of life.

The faith of the operation of God - They were quickened, changed, and saved, by means of faith in Christ Jesus; which faith was produced by the operation or energy of God. Believing is the act of the soul; but the grace or power to believe comes from God himself.