"neither yield your members instruments of unrighteousness to sin, but yield yourselves to God as alive from among the dead and your members instruments of righteousness to God" (Rom. 6.13 Darby).
This is the essential element of consecration. If we persist in holding on to something which God wants us to relinquish, sin shall have dominion over us, and our reckoning shall be futile. If we fail to yield our members as godly instruments of righteousness to speak and do what He desires and go where He directs, should we be surprised we are not yet delivered from sin! Whenever we refuse to relinquish or we offer resistance to God, sin shall return to its dominion. Under such circumstances we naturally lose the power to reckon, that is, to believe God's Word. In our ceasing to exercise faith and to reckon, can we still be said to be positionally in Christ? Yes, but we are living no longer in Him according to the sense of the "abide in me" of John 15. Accordingly we are unqualified to experience what is factual in Christ, even our crucifixion!
John 15:5 I am the vine, you are the branches. Whoever remains in union with me and I in union with him will bear abundant fruit, because you cannot do anything cut off from union with me.