1. Comparing our "strengths" to someone else's "weaknesses"--That would be called being haughty. "Haughty" is an adjective describing one who behaves in a superior, condescending, or arrogant way.Let's take a look at some examples of these in the Bible. First we'll look at someone who was haughty. Luke 18:9-14 (NKJV), Also He spoke this parable to some who trusted in themselves that they were righteous, and despised others:  “Two men went up to the temple to pray, one a Pharisee and the other a tax collector.  The Pharisee stood and prayed thus with himself, ‘God, I thank You, that I am not like other men--extortioners, unjust, adulterers, or even as this tax collector.  I fast twice a week, I give tithes of all that I possess.  And the tax collector, standing afar off, would not so much as raise his eyes to heaven, but beat his breast, saying, ‘God be merciful to me a sinner!’  I tell you, this man went down to his house justified rather than the other; for everyone who exalts himself will be humbled, and he who humbles himself will be exalted.”
2. Comparing our "weaknesses" to someone else's "strengths"--That would be called having an "Inferiority Complex." To me that's when someone has an overdeveloped sense of being inferior to others. In other words, that seems to be all they think about! Believe it or not, having and inferiority complex is just as much pride as being haughty, because the focus is all about self.
Notice the Pharisee compared himself to another man, but the tax collector (or "Publican" as the KJV says) compared himself to a Holy God. Go back and read the last verse again and see just which one ended up being lifted up.
Next, let's think about Moses, our example of one who had an Inferiority Complex. God showed up to him in a very powerful, supernatural way in a burning bush that was not consumed. God asked him to go lead the Israelites out Egypt where they were in captivity as slaves. Moses kept giving excuses why he shouldn't be the one to go. “Who am I that I should go?” “But I am not eloquent in speech.” “Can’t you send someone else?” All the while, God was proving He would be with him. Read it for yourself in Exodus 3 and 4. Thankfully, God still used Moses to lead the people out of Egypt and turn the tide of history setting the stage for people of God to be delivered for ages to come. It was certainly not because of Moses' abilities, or should we say lack or fears?
My prayer is that when God nudges me to do something, He will remind me to look to Him, and not compare myself to others or focus on my lack of abilities. I need to remember, as Paul said in Philippians 2:13 that it is God who works in me both to will and to do for His good pleasure. If He has put a desire in me, He will give me everything I need to accomplish it. He has promised to complete what He starts in me. Thank you, Lord!