Jude 20 But you, dear friends, build yourselves up in your most holy faith and pray in the Holy Spirit. 21 Keep yourselves in God's love as you wait for the mercy of our Lord Jesus Christ to bring you to eternal life.
22 Be merciful to those who doubt; 23 snatch others from the fire and save them; to others show mercy, mixed with fear—hating even the clothing stained by corrupted flesh.
24 To him who is able to keep you from falling and to present you before his glorious presence without fault and with great joy— 25 to the only God our Savior be glory, majesty, power and authority, through Jesus Christ our Lord, before all ages, now and forevermore! Amen.
I'm off into a busy day, but highly recommend John Calvin's Commentary on this section.
Especially helpful are his words concerning verse 23:
"When there is a danger of fire, we hesitate not to snatch away violently whom we desire to save; for it would not be enough to beckon with the finger, or kindly to stretch forth the hand. So also the salvation of some ought to be cared for, because they will not come to God, except when rudely drawn."