God calls all people, so our response starts with His call. Each one of us has been destined to be conformed to the image of his Son, but many of us fight against our destiny. God's destiny is never forced on us.
And I, when I am lifted up from the earth, will draw all people to myself. John 12:32 (ESV)
He is the propitiation for our sins, and not for ours only but also for the sins of the whole world. 1 John 2:2 (ESV)
For those whom he foreknew he also predestined to be conformed to the image of his Son, in order that he might be the firstborn among many brothers. And those whom he predestined he also called, and those whom he called he also justified, and those whom he justified he also glorified. Romans 8:29-30 (ESV)
We should never be prideful in our response to God or be haughty toward those who do not yet believe because our belief started with God.
We love because he first loved us. 1 John 4:19 (ESV)
For it is God who works in you, both to will and to work for his good pleasure. Phil 2:13 (ESV)
But we must respond to that love. God chose us, but we also must choose Him. Are we willing to do what He has called us to do?
And this commandment we have from him: whoever loves God must also love his brother. 1 John 4:21 (ESV)
If anyone would come after me, let him deny himself and take up his cross daily and follow me. Luke 9:23 (ESV)
We now play a part in the redemption of the world. Our part is meaningless without the sacrifice of Jesus, but His sacrifice gains meaning to those around us by our faithfulness to his call on our lives:
My brothers, if anyone among you wanders from the truth and someone brings him back, let him know that whoever brings back a sinner from his wandering will save his soul from death and will cover a multitude of sins. James 5:19-20 (ESV)
Let your light shine before others, so that they may see your good works and give glory to your Father who is in heaven. Matt 5:16 (ESV)
Finally, each one of us is perfect at birth yet born into a fallen world where we eventually choose to sin, which separates us from God. We are all in the Lamb's book of life. Some are, unfortunately, blotted out. Names written before the foundation of the world are blotted out. Tragic. We must become and remain faithful.
The one who conquers will be clothed thus in white garments, and I will never blot his name out of the book of life. Rev 3:5 (ESV)
For it is impossible, in the case of those who have once been enlightened, who have tasted the heavenly gift, and have shared in the Holy Spirit, and have tasted the goodness of the word of God and the powers of the age to come, and then have fallen away, to restore them again to repentance, since they are crucifying once again the Son of God to their own harm and holding him up to contempt. Heb 6:4-6 (ESV)