Our eye therefore is evil, if in any thing we do, we aim at any other end than God; if we have any view, but to know and to love God, to please and serve him in all things: if we have any other design than to enjoy God, to be happy in him both now and for ever. 7. If thine eye be not singly fixt on God, _thy whole body shall be full of darkness_. The veil shall still remain on thy heart. Thy mind shall be more and more blinded, by _the God of this world, lest the light of the glorious gospel of_ Christ _should shine upon thee_. Thou wilt be full of ignorance and error touching the things of God, not being able to receive or discern them. And even when thou hast some desire to serve God, thou wilt be full of uncertainty as to the manner of serving him; finding doubts and difficulties on every side, and not seeing any way to escape. Yea, if thine eye be not single, if thou seek any of the things of earth, thou shalt be full of ungodliness and unrighteousness: thy desires, tempers, affections, being all out of course, being all dark, and vile, and vain. And thy conversation will be evil, as well as thy heart, not _seasoned with salt_, or _meet to minister grace unto the hearers_, but idle, unprofitable, corrupt, grievous to the Holy Spirit of God. 8. *Both _destruction and unhappiness are in thy ways_; for _the way of peace hast_ thou _not known_. There is no peace, no settled, solid peace, for them that know not God. There is no true, nor lasting content for any, who do not seek him with their whole heart. While thou aimest at any of the things that perish, _all that cometh is vanity_. Yea, not only vanity, but _vexation of spirit_, and that both in the pursuit and the enjoyment also. Thou walkest indeed in a vain shadow, and disquietest thyself in vain. Thou walkest in darkness that may be felt. _Sleep on_; but thou canst not _take thy rest_. The dreams of life can give pain, and that thou knowest: but ease they cannot give. There is no rest, in this world or the world to come, but only in God the center of spirits. _If the light which is in thee be darkness, how great is that darkness!_ If the intention which ought to enlighten the whole soul, to fill it with knowledge, and love, and peace, and which, in fact, does so as long as it is single, as long as it aims at God alone: if this be darkness; if it aim at any thing beside God, and consequently cover the soul with darkness instead of light, with ignorance and error, with sin and misery: O how great is that darkness! It is the very smoke which ascends out of the bottomless pit! It is the essential night, which reigns in the lowest deep, in the land of the shadow of death. 9. Therefore _lay not up for yourselves treasures upon earth, where moth and rust doth corrupt, and where thieves break through and steal_. If you do, it is plain your eye is evil: it is not singly fixed on God.