May not true believers, by reason of their imperfections, and the many temptations and sins they are overtaken with, fall away from the state of grace?

#WLC79

True believers, by reason of the unchangeable love of God, and his decree and covenant to give them perseverance, their inseparable union with Christ, his continual intercession for them, and the Spirit and seed of God abiding in them, can neither totally nor finally fall away from the state of grace, but are kept by the power of God through faith unto salvation.

Proofs

True believers, by reason of the unchangeable love of God, (Jeremiah 31:3)
and his decree and covenant to give them perseverance, (2 Timothy 2:19; Hebrews 13:20–21; 2 Samuel 23:5)
their inseparable union with Christ, (1 Corinthians 1:8–9)
his continual intercession for them, (Hebrews 7:25; Luke 22:32)
and the Spirit and seed of God abiding in them, (1 John 3:9; 2:27)
can neither totally nor finally fall away from the state of grace, (Jeremiah 32:40; John 10:28)
but are kept by the power of God through faith unto salvation. (1 Peter 1:5)