Bible Verses About Prayer: With the spirit and understanding

ye worship what ye have not known; we worship what we have known, because the salvation is of the Jews;

but, there cometh an hour, and it now is, when the true worshippers will worship the Father in spirit and truth, for the Father also doth seek such to worship him;

God is a Spirit, and those worshipping Him, in spirit and truth it doth behove to worship.'

What then is it? I will pray with the spirit, and I will pray also with the understanding; I will sing psalms with the spirit, and I will sing psalms also with the understanding;