"Accept the one whose faith is weak, without quarreling over disputable matters. One person's faith allows them to eat anything, but another, whose faith is weak, eats only vegetables. The one who eats everything must not treat with contempt the one who does not, and the one who does not eat everything must not judge the one who does, for God has accepted them" (Romans 14:1-3, NIV).
Satan's greatest goal is not the individual acts of evil that you see, read about, or hear about. Every evil act is a result of something even more diabolical that began even before the beginning of time. His greatest goal is division. He came to seperate. He seperated from, became disconnected from, broke the "nexus" he had with God. He then set his sights on the first two physical creations that God placed His very breath within, to bring seperation between them and God and each other.
Look around. Seperation and division can be seen in the everyday as close to home as those around you. It's not wrong to disagree. God created you with a mind that dreams, thinks, comprehends in ways that are different than those around you. The purpose was never for division, but for diversity and creativity, so that you would know how incomplete you are alone, but complimented by those that think in ways that you don't. Sometimes, the disagreements will be such that you might never see it the same way as another. That is OK. You CAN agree to disagree without being condescending. Proving someone WRONG in an UNLOVING way isn't showing them Jesus. It only serves the further the goal the devil lives to achieve.
Agreeing to disagree isn't to compromise truth. It is to LIVE TRUTH and let the Holy Spirit of God work that truth through you. Becoming condescending only serves to contradict the love of Jesus and the truth of God you say you believe. Rely on the Holy Spirit to give you the strength to prove His love more than your point.