https://www.mljtrust.org/sermons-online/john-1-12-13/abraham-faith-in-action/

Can Christians have assurance of their salvation? This is not a merely speculative question, but it is at the heart of much of the Gospel. In this sermon on John 1:12-13, Dr. Martyn Lloyd-Jones preaches the great truth that those who are saved in Christ can and should know that they are redeemed! He looks at the example of Abraham who is told by God to go sacrifice his son, Isaac. Abraham goes because he trusts in God and in His promises. He does not doubt that God can even bring his son back from the dead! While God intervenes at the last moment so that Abraham does not have to sacrifice his son, Abraham’s faith and assurance in God is still displayed. Christians can see their assurance in their external actions, but also by recognizing that they are trusting in Christ. Those that have repented of their sins and rest wholly in Christ’s death can know that they are now safe in the arms of God. They can know that God loves them and has sent His Son to die for them! This is one of the most comforting truths in the Christians life and should be a great source of encouragement for all believers.