Sin Always Makes Us Feel Cut Off From God
Psalm 6:4 (ESV) … “Turn, O Lord, deliver my life; save me for the sake of your steadfast love.”
In Suffering God Seems Absent but Still the Holy Spirit Works in Us. John Knox:
It seems to David - being in the extremity of his pain—that God has altogether departed from him. For the flesh, indeed the whole person, always judges in this way when trouble continues for any duration of time. David had sustained trouble many days; he had prayed and yet was not delivered. And therefore, he judges that God, being offended by his sins, had left him. And yet it is plain that God was with him, working repentance in his heart by his Holy Spirit, expressing forth those sobs and groans, as well as the desire he had to be restored to that comfort and consolation which sometimes he had felt through the familiarity which he had with God.
All these motions, I say, were the operations of God’s Holy Spirit, and yet David could perceive no comfort or presence of God in his trouble but lamentably complains.… By this it is plain that even the elect themselves sometimes are without all feeling of consolation, and that they think themselves altogether destitute.… But David in his anguish remembers that God had formerly been familiar with him. For he says, “Turn again, O Lord,” indicating that before he had felt the sweetness of God’s presence, but now he was left to himself without comfort or consolation. 
 Selderhuis, H. J., George, T., Manetsch, S. M., & McNutt, D. W. (Eds.). (2015). Psalms 1–72: Old Testament (Vol. VII, pp. 56–57). Downers Grove, IL: IVP Academic.