明枪易躲，暗箭难防 meaning in English

it is easy to dodge an open spear thrust, but difficult to guard against an arrow in the dark.; it is easy to parry a spear-thrust in the open, but hard to evade an arrow shot in the dark.; it is easy to dodge a spear in the open, but hard to guard against an arrow shot from a hidden place.; a visible spear is easily withstood, but an unseen arrow is hard to guard against.; a spear openly discharged at you is easy to avoid, but it is difficult to guard against such as are discharged in secret.; better an open enemy than a false friend