Yes, Jesus is fully God. But He is also fully Man. And it was as a Man that He defeated temptation.
“As a Man, without using any of His divine powers, Jesus defeated temptation in the same areas where Eve failed and where we fail. … By this He condemned sin in sinful man, that is, He showed we sin, not because we have to sin, but because we choose to sin and because we ignore the help available through the Word and the Spirit.” —Stanley Horton
We don’t have to sin, but we choose to sin.
“In His temptation, Jesus did not use His divine power to defeat the devil. Still identifying Himself with us as Spirit-filled human, He defeated satan by the same means that are available to us — the Word, anointed by the Spirit. Eve, tempted in exactly the same areas—the lust of the flesh (appetite), the lust of the eyes (desire), and the pride of life—failed (Genesis 3:6; 1 John 2:16). In these areas, which John says together comprise the things of the world or worldliness (1 John 2:15). Jesus won a complete victory for us. He has truly overcome the world (John 16:33). We can do the same by our faith (1 John 5:4).” —Stanley Horton
We can do the same thing. Instead of saying, “I gave in to temptation,” we can say, “I gave in to the Holy Spirit, Who helped me defeat temptation!”