We have both an outward call of God and an inward call of God.
R.C. Sproul writes:
"The outward call of God comes from the preaching of His word. Many share the gospel with others, but not all who hear the message receive it. The outward call of God can be resisted. In fact, apart from God's working in us, we will resist this call (ie total depravity).
"The inward call of God is His secret work of regeneration (rebirth, a new beginning, spiritual resurrection) done in the souls of the elect by the work of the Holy Spirit. This work of the Holy Spirit changes us. God places within us a desire for Him. Before the inward call of God, no person is inclined to come to Him. After the inward call, we respond to God with the gift of faith. The inward call of God cannot be resisted."
Ezekiel 36:26-27 "I will give you a new heart and put a new spirit within
you; I will take the heart of stone out of your flesh and give you a heart of
flesh. 'I will put My Spirit within you and cause you to walk in My statutes,
and you will keep My judgments and do them.'" (NKJ)
II Thessalonians 2:13-14 "But we are bound to give thanks to God always
for you, brethren beloved by the Lord, because God from the beginning chose you
for salvation through sanctification by the Spirit and belief in the truth, to
which He called you by our gospel, for the obtaining of the glory of our Lord
Jesus Christ." (NKJ)
"God's grace prevails over our natural resistance for those whom he has chosen." - R.C. Sproul