as a designation of Christians, means full of faith, trustful, and not simply trustworthy (Acts 10:45;16:1; 2-Cor 6:15; Col. 1:2; 1-Tim 4:3, 1-Tim 4: 12;5:16;6:2; Titus 1:6; Eph. 1:1; 1-Cor 4:17, 1-Cor 4: etc.).
It is used also of God's word or covenant as true and to be trusted (Psa 119:86, Psa 119: 138; Isa. 25:1; 1-Tim 1:15; Rev. 21:5;22:6, 22: etc.).