That doesn’t sound very romantic; “tolerate” seems a pretty low bar to hurdle in the context of marriage. One of its definitions though is “accept,” and that is key. Romans 15:7 says explicitly “Accept one another.” Too often we expect the other person to change when things aren’t going smoothly. There is an old adage “Women enter marriage expecting their husband to change, and they don’t. Men enter marriage expecting their wife to stay the same… and they don’t.” It is critical that we accept the person our spouse IS at any given point in time. We can’t pine for who they were, and yearn for who they could be. Our job is not to change them, mold them or shape them, but to encourage them and love them. When a person is set on changing another, disappointment is almost guaranteed. The vows we took were not stated with conditions; they were absolutes. We promised to love, to keep, to cherish. When acceptance is the goal, peace is much more often the outcome. As for the rest of this verse, gentleness and patience are both fruits of the spirit, and are qualities to be sought as we deal with all people. How much more so should we seek them when dealing with the person we have chosen to go through life with?
Even when our partners falter, we are called to be like Christ. The natural human reaction is to seek retribution, to punish the one at fault but again, that is not our job. 1 Thessalonians 5:15 says we are “not to repay evil with evil” but instead we should “seek good for one another.” This is not easy when we are hurting, but if we can look beyond the behavior we may see the other person is hurting too. Or scared, stressed or anxious. We must focus on forgiveness, on healing, on wholeness.