John 10:10: The Life Jesus Came to Give
Jesus says he came on purpose to give life, and to give it abundantly. The verse defines that abundance by who he is and by the safety of belonging to him, not by guaranteed circumstances.
John 10:10: The Thief vs. the Good Shepherd
In John 10:10 the thief is not a bad mood or a hard circumstance but a false claimant to the sheep, one who climbs in another way than the door. The answer is not a technique for feeling better but a settled attachment to the shepherd who owns the sheep and lays down his life for them.