(I encourage you to look up the references below.)
If we profess to be God’s people, we should reflect his character. We are to be like He is.
So, what does the Bible say about God and truth?
The Scriptures clearly teach that God is a God of Truth (Deu.32:4; Ps.31:5). If we define the word "truth" and apply its meaning to God, we can say that God is trustworthy, genuine, honest, and consistent with reality. He is correct and accurate, unwavering, and fixed or stable. That God is a God of Truth means much more than "God does not tell lies." It means that God is perfect (Mat.5:48), that He never varies (Jas.1:18), that He is good and upright in every way (Psa.25:8), that He is righteous in all His ways (Psa. 145:17), holy in all His works (Psa.145:17), just (Isa.45:21), and faithful (Isa.49:7; 1Co.1:9).
The Bible also informs us that when God chose to reveal Himself, He gave us the Word of Truth (Joh.17:17; 2Ti.2:15). This Truth was ultimately given in the person of Christ (Joh.1:17), who was himself Truth (Joh.1:14; 14:6). When Christ finished His earthly work and returned to the Father, He gave us the Spirit of Truth (Joh.14:17; 15:26; 1Jo.5:6).
In contrast to God's truth, those who reject or deny God are described as people who "hold the truth of God in unrighteousness" (Rom.1:18). They are said to be those who "changed the truth of God into a lie" (Rom.1:25). False teachers are described as those who are "destitute of the truth" (1Ti.6:5). They are able to lead away people who are "ever learning, but never able to come to the knowledge of the truth" (2Ti.3:7). Jesus said to the Pharisees, "Ye are of your father the devil . . . [who] abode not in the truth, because there is no truth in him" (Joh.8:44). The wicked experience God's judgment because "they received not the love of the truth, that they might be saved" (2Th.2:10).
But by God's grace, there are those who "come to the knowledge of the truth" (1Ti.2:4). Just as those who do evil hate the light, he "that doeth truth cometh to the light" (Joh.3:21). Those who seek the truth in God's Word shall find it (Joh.8:32), but it is found only in God's Word (Joh.17:17; 2Ti.2:15). When we practice God’s ways, we are of the truth (1Jo.3:18-19). We should then join with others who, united, form a stronghold of truth (1Ti.3:15). Since we have purified our souls through truth (1Pe.1:22), we are to speak the truth (Eph.4:15,25). We are to be established firmly in the truth (Eph.6:14), and we are to rejoice in the truth (1Co.13:6). Christians are to discern the spirit of truth (1Jo.4:6; Isa.8:20); indeed, we are to live in truth (Eph.5:9). And we must be careful not to cause those outside Christ to ridicule the way of truth (2Pe.2:2).
It should be clear that we, as Christians, are to mirror the character of God respecting truth. Others should know that we are a people of Truth; that we are trustworthy, genuine, honest; that we demonstrate reality, that we are accurate, unwavering, and stable. Being a people of truth should mean that we strive to be perfect (Mat.5:48), that we never vary (Psa.15:4), that we are good and upright in every way (Pro.11:3,6), that we are righteous in all our ways (Pro.11:5), holy in all our works (Lev.11:44,45; 20:7), just (Pro.3:33; 20:7), and faithful (Pro.20:6, 2Ti.2:2).
Christians - God's people - are set as a light in a world of darkness; as the genuine amidst the false. We, in Him, are the sound among the decrepit; the healthy surrounded by the sick. We, by knowing Christ, can know and enjoy reality while those outside of Christ go on pretending the illusion. We who know Him who is Truth are being conformed to His image, have been reborn into His likeness, and have been instilled with His character by His Spirit. Let us forsake the false, reject the empty, despise the pretended; and, in truth, serve the God of Truth. Let us be, in reality, a people of Truth.