His affections will be fixed on Jesus-not perfectly but purposefully. Since his will is changed in regeneration he will now have a desire to do the will of God despite of many failures. He will not fall into the ditch of presumption because in front of the ditch of presumption there is a hedge row of God's precepts. Nor will he fall into the ditch of despair because in front of the ditch of despair there is a hedge row of God's promises. Yes, Christians can and do sin and sometimes grievously.
Christians can stumble and fall and they make many crooked steps on their way to the Celestial City.
Yes, they can grow cold and they do. Yes, there are failures and sometimes serious failures. Though the winds of temptation and weakness may blow their little ship off course, nevertheless, when the storm subsides they will always get on course again. The Non-Lordship teaching on regeneration would hold that it is the supernatural work of God whereby the sinner is imparted new life, but not necessarily the transformation of life. Changes may or may not take place in the life of the supposed convert.