This is a very clear passage. If the believer could grieve the Spirit of God, so that He must withdraw His presence from the believer, here is the place to state the possibility. On the contrary there is no such warning. The positive statement is given is given that the sealing is " unto the day of redemption," that is until the day comes when the Lord at His second coming will translate His church to glory.
We read,
that is to say that God will never change His mind, and withdraw any gift He gives, or calling He makes. When God gives a gift, or makes a calling, He never withdraws His bounty. So it is with the gift of the Spirit of God. Once given it is never withdrawn.
Typically in the consecration of Aaron and his sons, we find the oil (typical of the Holy Spirit) was put upon the blood (typical of the atoning sacrifice of Christ applied in all its blessed efficacy). This is the reason why the Spirit is never withdrawn, because the indwelling is vouchsafed on the righteous ground of the finished atoning work of our Lord on the cross. All glory to His blessed name!