السَّعِيدُ قَدْ يَشْقَى بِأَنْ يَرْتَدَّ بَعْدَ الإِيمَانِ
One described as blessed may become wretched through apostasy after faith.
Blessedness may describe present faith and hope, or it may refer to ultimate salvation. Similarly, wretchedness may describe a current state of unbelief or a final outcome.
These different reference points must be distinguished. A person can change from faith to disbelief or from disbelief to faith. This means the person's condition changes; it does not imply any alteration in God's eternal knowledge.