"Indeed it was for my own peace that I had great bitterness; But You have lovingly delivered my soul from the pit of corruption, for You have cast all my sins behind Your back."
This is something we feel. True religion is a feeling religion.
First, we don't rely on how we feel. Faith grabs the written word of God and holds on tenaciously; it believes against all unbelief, because the testimony is real; it is not dependent upon man.
Secondly, true Christianity has feeling. You feel pardon and forgiveness of sins! You feel God draw near. You feel the way of heaven opened, and you feel the joy and peace.
Thirdly, we feel because sins are pardoned. “You cast all my sins behind Your back.” Charlest Spurgeon calls this, "an Almighty arm," and indeed it is. “He will again have compassion on us; he will tread our iniquities underfoot. You will cast all our sins into the depths of the sea [Micah 7:19].” To cast our sins required the blood of the cross, when God's own Son was made to pay for them, so they could be put away. It required justice to be satisfied in the death of Christ.
Fourthly, we feel by the POWER OF THE HOLY SPIRIT! This is why He's so important, because we're locked out of the joys of religion without His presence, so we enslave ourselves to Christ - a gentle Master - lest He depart through offense. “And do not grieve the Holy Spirit of God, in whom you were sealed for the day of redemption. [Eph 4:30].” We obey and diligently follow His precepts! We put obedience before everything in life.
Fifthly, when comfort is lacking, like Hezekiah, chatter before God's throne in mournful sorrow. “Like a swallow or a crane I chirp; I moan like a dove. My eyes are weary with looking upward [Isa 38:14].” Turn your back to the world and seek Him [Isa 38:2]. He may use an avalanche of scripture, prayer, and exhortations to deliver you. Honor Him by going nowhere else for comfort.
Come to Him, until your joy is full. We may lose privileges and opportunities, but we cannot lose Christ. We can be comforted with every other loss in the world.
Finally, be hopeful and optimistic: He will return to you, and you will enjoy God, which is the highest joy of the soul.