As members of the Catholic Church that Jesus Christ founded, we receive the physical Body and Blood of Christ in the Eucharist along with the graces that are necessary for our eternal life.
It is sad that some do not have Faith in the Real Presence of Christ in the Eucharist that is necessary for their salvation.
A believers in Christ has Christ indwelling in them in addition to the Holy Spirit.
Christ is always with the believer as is the Holy Spirit. They do not depart the believer.
13In Him, you also, after listening to the message of truth, the gospel of your salvation—having also believed, you were sealed in Him with the Holy Spirit of promise, 14who is given as a pledge of our inheritance, with a view to the redemption of God’s own possession, to the praise of His glory. Ephesians 1:13-14 NASB
24“Truly, truly, I say to you, he who hears My word, and believes Him who sent Me, has eternal life, and does not come into judgment, but has passed out of death into life. John 5:24 NASB
67So Jesus said to the twelve, “You do not want to go away also, do you?” 68Simon Peter answered Him, “Lord, to whom shall we go? You have words of eternal life. 69“We have believed and have come to know that You are the Holy One of God.” John 6:67-69 NASB
We come to Christ through belief in Him.
We are sealed by the Spirit.
No where does the NT ever record the believer as being unsealed.