"Oh, I haven't been to Church in years...I don't really know why, I just stopped going..."
"I realize that my life has become dominated by things I don't even like..."
"It all feels pointless..."
Perhaps you do not know exactly why you no longer practice your faith, but you now found you have drifted away. Or, perhaps it was a bad experience with a certain priest that pushed you away; perhaps you took issue with a Church teaching and decided you were done; perhaps you decided you just didn't have time; perhaps you stopped practicing to appease or please somebody else -- a spouse, a parent, a friend, or a child.
But you know in your heart of hearts that where you are now is not where you are supposed to be, nor is it where you even want to be.
As the allurements of the world and the flesh continue to reveal to you their true colors with each successive disappointment you now must endure, recall to mind the inner peace you abandoned for their sake.
What, even now, holds you back? Financial investments? Your money will soon be worthless. Material possessions? Do you not sometimes find yourself daydreaming of being rid of them and the burden they have become? Human relationships? What makes you so certain that these mere humans, to whom you are attached, will live to see tomorrow? They too shall perish, perhaps before you. Even aside from that, you yourself know full well that you cannot depend upon any person on this Earth to fulfill your heart; need you be reminded of the times each person in your life has already failed you in some way? God allows these failures not so that you can withhold forgiveness or love them less -- but only to remind you that He alone can ultimately satisfy, and to give you the grace to be detached from other people.
Your life does not have to continue on in this manner; on the contrary, your time away from Church, though not a good thing in itself, will now, if you choose rightly, only serve to increase your gratitude as you come back home.
There is no sin you could have possibly committed that is anything but a grain of sand dropped into the ocean of God's mercy, and there is no struggle that returning to the Faith will bring that God's abundant grace will not carry you through.
If you are a lapsed Catholic, there is no way back home except through the Holy Catholic Church. Many who by no fault of there own could not see the truth in Catholicism will find happiness in this life and Heaven in the next without it. But you are not one of those people. By Baptism you have entered into the Body of Christ. Through Confirmation you have been granted the gift of the Holy Spirit. By receiving Communion you have partaken of the Heavenly Banquet. Never again will anything else satisfy or save. Your heart will remain restless until it rests in Him, through His bride, the Catholic Church.