"If your brother or sister is distressed because of what you eat, you are no longer acting in love. Do not by your eating destroy someone for whom Christ died" (Romans 14:15, NIV).
The change God works in those around you may NOT look just like what He's working in you. Don't judge. Don't intimidate. Don't manipulate. Love. Trying to get someone to change and become more like you, especially when it is the "gray areas" of personal conviction and not absolute truth, does more to lead them to push back than to press on. Love them where they are and let God meet them there. Most of us are never pushed closer to God. We are drawn closer. Showing love will keep the conversation going and the relationship between you and the other growing. Let love lead you in your nexus with others, rather than your disappointment in where you expect them to be in their relationship with God.
Love leads you to care more about where someone IS than where YOU want them to be. Love them there & let God work. As God is not finished working in you, He's not finished working through you or in the lives of those around you. When it's black and white, love them enough to point it out, show them love, and help them to work it through. If it's not black and white in the Scripture, even though it feels black and white, full color, high definition, and three dimensional to you, slow down, back off, show love, and let God work. Or, acknowledge that where God has them may be different than where God has you. Don't allow judgment or jealousy to have a foothold. Keep loving and growing stronger in your connection with God and with one another.