1Co 15:21 For as by a man came death, by a man has come also the resurrection of the dead.
1Co 15:22 For as in Adam all die, so also in Christ shall all be made alive.
1Co 15:23 But each in his own order: Christ the firstfruits, then at his coming those who belong to Christ.
1Co 15:24 Then comes the end, when he delivers the kingdom to God the Father after destroying every rule and every authority and power.
1Co 15:58 Therefore, my beloved brothers, be steadfast, immovable, always abounding in the work of the Lord, knowing that in the Lord your labor is not in vain.
Be steadfast in biblical truth, unwavering. The truth begins at the Beginning in Genesis (reference to Adam which confirms the historicity of Gen. 2-3) all the way through Salvation and on to the End. Denying any part is being unfaithful and wavering, movable, and cowardly.