Yes, we can lose people we love by sinning. We can lose them as friends, we can discourage them as believers and, in some cases, we may even lose them completely to unbelief and destruction. In particular, parents can lose their children. There are examples of each of these in the Bible.
Believers are meant to encourage each other in godliness through a good example (Philippians 3:17, Hebrews 10:24). If we sin instead, we can lead them astray and Jesus announces his condemnation of this:
And he said to his disciples, “Temptations to sin are sure to come, but woe to the one through whom they come! It would be better for him if a millstone were hung around his neck and he were cast into the sea than that he should cause one of these little ones to sin.” (Luke 17:1-2)
Examples of people who have lost those they loved through sin:
- Rebecca had to send her younger son Jacob far away from home because of her crafty plot to trick Isaac her husband into blessing him instead of the oldest son Esau. The plan worked, but Esau wanted to kill Jacob as a result. Rebecca probably never saw Jacob again. See Genesis 27:1 – 28:5.
- Eli failed to restrain his sons and they were killed in battle as punishment (1 Samuel 2:27-34, 3:12-14, 4:10-11).
- Jereboam the son of Nebat, famous as the king who taught Israel to sin, lost his son because of his sin (1 Kings 14:6-16).
- David lost the friendship and faithful service of his adviser Ahithophel probably because of his adultery with Bathsheba and the killing of her husband Uriah.
- David failed to restrain his son Adonijah, and lost him through rebellion (1 Kings 1:5-6).
- Judas lost Jesus as his saviour though his sin and betrayal. Jesus said of him that it would have been better if he had never been born (Matthew 26:24). He travelled with Jesus for years, but lost him through sin.
- As an example that ended positively, Peter could have lost Jesus also after his denial of him (Mark 14:66-72) – but he did not give up; he repented, and was forgiven.