The redeemed are held and secured by a threefold cord which can never be broken!

Each of the three Persons in the blessed Trinity is concerned with our salvation:
  with the Father it is predestination;
  with the Son it is redemption;
  with the Spirit it is regeneration.

The Father chose us;
the Son died for us;
the Spirit quickens us. (Arthur Pink)

In the affair of man's salvation . . .
  election is ascribed to the Father,
  reconciliation is ascribed to the Son, and
  sanctification is ascribed to the Holy Spirit. (Mathew Henry)

The redeemed are held and secured by a threefold cord which can never be broken!
1. By God the FATHER, who . . .
  has loved them with an everlasting love,
  has chosen them in Christ,
  has secured them in the covenant of grace,
  has given them saving grace,
  keeps them by His power,
  and will give them eternal glory!

2. By the SON, who . . .
  has undertaken the work of salvation for them,
  has redeemed and purchased them,
  prays and intercedes for them,
  makes preparations in Heaven for them.
They are built on Him, united to Him, and are His jewels, whom He cherishes and will preserve.

3. By the HOLY SPIRIT . . .
  whose grace is incorruptible,
  whose personal indwelling is forever,
  who Himself is the pledge and seal of their heavenly inheritance,
  who having begun, will finish the good work of grace. (John Gill)

"Blessed be the God and Father of our Lord Jesus Christ, who has blessed us with every spiritual blessing in the heavenly places in Christ; just as He chose us in Him before the foundation of the world, that we would be holy and blameless before Him. In love He predestined us to adoption as sons through Jesus Christ to Himself, according to the kind intention of His will, to the praise of the glory of His grace, which He freely bestowed on us in the Beloved." Ephesians 1:3-6