The first marker of Christlike maturity that Paul identifies in Ephesians 4 is humility. To grow in Christ is to grow in your understanding of just how far short of the goal of Christlikeness you fall and how incapable you are of achieving that goal on your own you are. As you grow in humility it leads you to be gentler and more forgiving with others. As you grow in your awareness of how patient God is with you, it makes you more patient towards others more able to bear with others, which makes unity with other fallible and faltering followers of Jesus more attainable.