'True God' in the Bible

But at that time, when you did not know [the true] God and were unacquainted with Him, you [Gentiles] were slaves to those [pagan] things which by [their very] nature were not and could not be gods at all.

not [to be used] in lustful passion, like the Gentiles who do not know God and are ignorant of His will;

And we [have seen and] know [by personal experience] that the Son of God has [actually] come [to this world], and has given us understanding and insight so that we may [progressively and personally] know Him who is true; and we are in Him who is true—in His Son Jesus Christ. This is the true God and eternal life.