It is not that the truth is sin (or vice-versa). Rather, it is Sin that is the master (or “lord”) of the one who sins.1 That is, Sin is the enslaver; the sinner is the enslaved.
The apostle Paul describes how Sin (personified)1 holds the unregenerate person enslaved and captive before his regeneration.
“For Sin shall not be master over you.”2 (The corollary is that Sin is indeed the master over the unregenerate sinner.) “Do not let Sin reign in your mortal body, so that you should obey it in its lusts.”3 (The corollary is that Sin does indeed reign in the mortal body of the unregenerate sinner, and the sinnner does obey Sin and its lusts.) Hence, “You were Sin’s servants...,”4 and obeyed Sin.5 “I am carnal, sold under Sin.”6 Like a slave sold into slavery and now under the servitude of a master, the unregenerate is “sold under Sin.”
1 Southall, p. 98
2 Rom. 6:14
3 Rom. 6:12
4 Rom. 6:17, 6:20
5 Rom. 6:16
6 Rom. 7:14
Not only does the unregenerate serve Sin as his master, but Sin dwells in (i.e., indwells) the unregenerate.7 With the flesh, the unregenerate obeys Sin’s law.8
7 Rom. 7:17, 20
8 Rom. 7:25
9 Rom. 7:8
“You shall know the truth, and the truth shall liberate you.” From what/whom does man need liberation? That is, under what/whom is he enslaved? The answer is: Sin.The apostle Paul wrote, “For he who is dead is liberated from Sin.”10 “Being liberated from Sin...”11 “The law of the Spirit of life in Christ Jesus has liberated me from the law of Sin and Death.”12
10 Rom. 6:7
11 Rom. 6:18. 6:22
12 Rom. 8:2
The Lord Jesus Christ is “the Way, the Truth, and the Life.”13 Knowing Jesus Christ is eternal life.14 Moreover, knowing the truth, the Lord Jesus Christ, will liberate you from the servitude of Sin as your master so that you can serve the Lord Jesus Christ,
22 But now being liberated from Sin, and becoming God’s servants, you have your fruit unto holiness, and the end everlasting life. 23 For Sin’s wages is death, but God’s gift is eternal life through Jesus Christ our Lord.
13 John 14:6
14 John 17:3
15 Rom. 8:2
15 Rom. 6:22–23
Southall, David J. Rediscovering Righteousness in Romans. Tübingen: Siebeck, 2008.