Philippians 1:6 - Jesus is Faithful!

Being confident of this very thing, that he which hath begun a
good work in you will perform it until the day of Jesus Christ: Phil
1:6 (KJV)

The God who began a good work in us continues it throughout our
lifetime and will finish it when we meet him face to face. God's work
'for' us began when Christ died on the cross in our place. His work
'in' us began when we first believed. Now the Holy Spirit lives in
us, enabling us to be more like Christ every day. Paul is describing
the process of Christian growth and maturity that began when we
accepted Jesus and continues until Christ returns. [Life Application SB]

The Lord is a perfect workman. He completes every work to which
He sets His hand, if only the human material permits Him to do so.
Furthermore, the product of such workmanship will be perfect. And He does not
weary in well-doing. [SDA Commentary]

There are those who have known the pardoning love of Christ and
who really desire to be children of God, yet they realize that their
character is imperfect, their life faulty, and they are ready to doubt
whether their hearts have been renewed by the Holy Spirit. To such I
would say, Do not draw back in despair. We shall often have to bow
down and weep at the feet of Jesus because of our shortcomings and
mistakes, but we are not to be discouraged. Even if we are overcome by the
enemy, we are not cast off, not forsaken and rejected of God. No;
Christ is at the right hand of God, who also maketh intercession for
us. Said the beloved John, "These things write I unto you, that ye
sin not. And if any man sin, we have an advocate with the Father,
Jesus Christ the righteous." 1 John 2:1. And do not forget the words
of Christ, "The Father Himself loveth you." John 16:27. He desires
to restore you to Himself, to see His own purity and holiness
reflected in you. And if you will but yield yourself to Him, He that hath
begun a good work in you will carry it forward to the day of Jesus
Christ. Pray more fervently; believe more fully. As we come to distrust
our own power, let us trust the power of our Redeemer, and we shall
praise Him who is the health of our countenance. SC64-5

What God begins, He completes.  This should bring comfort to
each one who knows Jesus Christ personally.  He began the "good work"
in you when the Holy Spirit moved upon your mind to draw you to
Jesus; He softened your heart and ordered circumstances for your
conversion.  In the very same way that He orchestrated your new birth, He
also now directs your new life.  Oh, don't misunderstand; you have a
part to play.  It is a responsive one.  He calls, you follow; He
directs, you obey.  And so the "good work" in you is being carried on!
Are you following?  Are you obeying?  Today is a great day to press
on in both these areas!  [In His Time; Walk With Wisdom]