Saul tried to convince David that he could not fight Goliath.
And Saul said to David, Thou art not able to go against this Philistine to fight with him: for thou art but a youth, and he a man of war from his youth. (1 Samuel 17:33)
David`s own brother sought to discourage him also.
And Eliab his eldest brother heard when he spake unto the men; and Eliab’s anger was kindled against David, and he said, Why camest thou down hither? and with whom hast thou left those few sheep in the wilderness? I know thy pride, and the naughtiness of thine heart; for thou art come down that thou mightest see the battle.
(1 Samuel 17:28)
If God has given you a work to do, then don’t let others discourage you by saying that it can’t be done or that you are the wrong person for the job.
David replied by recalling how God had enabled him to kill a lion and a bear.
Thy servant slew both the lion and the bear: and this uncircumcised Philistine shall be as one of them, seeing he hath defied the armies of the living God. (1 Samuel 17:36)
When we REMEMBER God’s goodness to us it should encourage us.
That’s why Israel was gripped by fear of Goliath, because they seemed to FORGET God’s deliverances in the past.
And all the men of Israel, when they saw the man, fled from him, and were sore afraid. (1 Samuel 17:24)
REMEMBER…..RECALL…REVIEW…..and RENEW your strength, through God.